Reinsurance Receivables.
Reinsurance receivables for both paid and recoverable on unpaid losses totaled $1,348,226 thousand and $1,018,325 thousand at December 31, 2017 and 2016, respectively.
At December 31, 2017, $356,556 thousand, or 26.4%, was receivable from Mt.
Logan Re collateralized segregated accounts; $153,815 thousand, or 11.4%, was receivable from Resolution Group Reinsurance (Barbados) Limited (“Resolution Group”); $113,922 thousand, or 8.4%, was receivable from Zurich Vericherungs Gesellschaft (“Zurich”); $98,121 thousand, or 7.3%, was receivable from C. V.  Starr (Bermuda) (“C.
V.  Starr”); and $82,234 thousand, or 6.1%, was receivable from Munich Reinsurance America, Inc.  (“Munich Re”).
The receivables from Resolution Group and C. V.  Starr are fully collateralized by individual trust agreements.
No other retrocessionaire accounted for more than 5% of our receivables.
Future Policy Benefit Reserve.
Activity in the reserve for future policy benefits is summarized for the periods indicated:
## Table 0 ##
4.
FAIR VALUE GAAP guidance regarding fair value measurements address how companies should measure fair value when they are required to use fair value measures for recognition or disclosure purposes under GAAP and provides a common definition of fair value to be used throughout GAAP.
It defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly fashion between market participants at the measurement date.
In addition, it establishes a three-level valuation hierarchy for the disclosure of fair value measurements.
The valuation hierarchy is based on the transparency of inputs to the valuation of an asset or liability.
The level in the hierarchy within which a given fair value measurement falls is determined based on the lowest level input that is significant to the measurement, with Level 1 being the highest priority and Level 3 being the lowest priority.
The levels in the hierarchy are defined as follows: Level 1: Inputs to the valuation methodology are observable inputs that reflect unadjusted quoted prices for identical assets or liabilities in an active market; Level 2: Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument; Level 3: Inputs to the valuation methodology are unobservable and significant to the fair value measurement.
The Company’s fixed maturity and equity securities are primarily managed by third party investment asset managers.
The investment asset managers obtain prices from nationally recognized pricing services.
These services seek to utilize market data and observations in their evaluation process.
They use pricing applications that vary by asset class and incorporate available market information and when fixed maturity securities do not trade on a daily basis the services will apply available information through processes such as benchmark curves, benchmarking of like securities, sector groupings and matrix pricing.
In addition, they use model processes, such as the Option Adjusted Spread model to develop prepayment and interest rate scenarios for securities that have prepayment features.
On November 18, 2014, the Company entered into a collateralized reinsurance agreement with Kilimanjaro to provide the Company with catastrophe reinsurance coverage.
This agreement is a multi-year reinsurance contract which covers specified earthquake events.
The agreement provides up to $500,000 thousand of reinsurance coverage from earthquakes in the United States, Puerto Rico and Canada.
On December 1, 2015 the Company entered into two collateralized reinsurance agreements with Kilimanjaro Re to provide the Company with catastrophe reinsurance coverage.
These agreements are multi-year reinsurance contracts which cover named storm and earthquake events.
The first agreement provides up to $300,000 thousand of reinsurance coverage from named storms and earthquakes in the United States, Puerto Rico and Canada.
The second agreement provides up to $325,000 thousand of reinsurance coverage from named storms and earthquakes in the United States, Puerto Rico and Canada.
On April 13, 2017 the Company entered into six collateralized reinsurance agreements with Kilimanjaro to provide the Company with annual aggregate catastrophe reinsurance coverage.
The initial three agreements are four year reinsurance contracts which cover named storm and earthquake events.
These agreements provide up to $225,000 thousand, $400,000 thousand and $325,000 thousand, respectively, of annual aggregate reinsurance coverage from named storms and earthquakes in the United States, Puerto Rico and Canada.
The subsequent three agreements are five year reinsurance contracts which cover named storm and earthquake events.
These agreements provide up to $50,000 thousand, $75,000 thousand and $175,000 thousand, respectively, of annual aggregate reinsurance coverage from named storms and earthquakes in the United States, Puerto Rico and Canada.
Recoveries under these collateralized reinsurance agreements with Kilimanjaro are primarily dependent on estimated industry level insured losses from covered events, as well as, the geographic location of the events.
The estimated industry level of insured losses is obtained from published estimates by an independent recognized authority on insured property losses.
As of December 31, 2017, none of the published insured loss estimates for the 2017 catastrophe events have exceeded the single event retentions under the terms of the agreements that would result in a recovery.
In addition, the aggregation of the to-date published insured loss estimates for the 2017 covered events have not exceeded the aggregated retentions for recovery.
However, if the published estimates for insured losses for the covered 2017 events increase, the aggregate losses may exceed the aggregate event retentions under the agreements, resulting in a recovery.
Kilimanjaro has financed the various property catastrophe reinsurance coverages by issuing catastrophe bonds to unrelated, external investors.
On April 24, 2014, Kilimanjaro issued $450,000 thousand of notes (“Series 2014-1 Notes”).
On November 18, 2014, Kilimanjaro issued $500,000 thousand of notes (“Series 2014-2 Notes”).
On December 1, 2015, Kilimanjaro issued $625,000 thousand of notes (“Series 2015-1 Notes).
On April 13, 2017, Kilimanjaro issued $950,000 thousand of notes (“Series 2017-1 Notes) and $300,000 thousand of notes (“Series 2017-2 Notes).
The proceeds from the issuance of the Notes listed above are held in reinsurance trust throughout the duration of the applicable reinsurance agreements and invested solely in US government money market funds with a rating of at least “AAAm” by Standard & Poor’s.9.
OPERATING LEASE AGREEMENTS The future minimum rental commitments, exclusive of cost escalation clauses, at December 31, 2017, for all of the Company’s operating leases with remaining non-cancelable terms in excess of one year are as follows:
## Table 1 ##
Premiums.
Gross written premiums increased by 22.0% to $2,593.0 million in 2017 from $2,125.8 million in 2016, primarily due to an increase in the new crop reinsurance business, an increase in treaty property business and the influx of reinstatement premiums due to the catastrophe losses and an increase in mortgage business.
Net written premiums increased by 13.9% to $2,245.4 million in 2017 compared to $1,970.6 million in 2016.
The difference between the change in gross written premiums compared to the change in net written premiums is primarily due to varying utilization of reinsurance.
Premiums earned increased by 5.3% to $2,181.2 million in 2017, compared to $2,072.2 million in 2016.
The change in premiums earned relative to net written premiums is primarily the result of changes in the mix of business and timing; premiums are earned ratably over the coverage period whereas written premiums are recorded at the initiation of the coverage period.
Gross written premiums decreased by 1.0% to $2,125.8 million in 2016 from $2,147.9 million in 2015, primarily due to a decrease in treaty property business, partially offset by an increase in treaty casualty business.
Net written premiums increased by 6.2% to $1,970.6 million in 2016 compared to $1,855.9 million in 2015.
The difference between the change in gross written premiums compared to the change in net written premiums is primarily due to the assumption of the crop business due to the sale of Heartland and a concurrent new crop reinsurance contract.
Premiums earned increased 6.1% to $2,072.2 million in 2016, compared to $1,952.7 million in 2015.
The change in premiums earned relative to net written premiums is primarily the result of timing; premiums are earned ratably over the coverage period whereas written premiums are recorded at the initiation of the coverage period.
Incurred Losses and LAE.
The following table presents the incurred losses and LAE for the U. S.  Reinsurance segment for the periods indicated.
## Table 2 ##
Incurred losses increased by 52.8% to $1,632.8 million in 2017, compared to $1,068.5 million in 2016, primarily due to an increase of $581.6 million in current year catastrophe losses, partially offset by $39.1 million of more favorable development on prior years attritional losses in 2017 compared to 2016.
The $165.5 million of favorable development on prior years attritional losses in 2017 was mainly related to property and short tail business.
The $715.7 million of current year catastrophe losses in 2017 related to Hurricane Irma ($331.8 million), Hurricane Harvey ($204.3 million), the Northern California wildfires ($132.9 million), Hurricane Maria ($31.2 million), the Southern California wildfires ($9.6 million), and the 2017 US Midwest storms ($6.9 million).
The $134.1 million of current year catastrophe losses in 2016 related to Hurricane Matthew ($86.2 million), the 2016 U. S.  storms ($20.4 million), 2016 Tennessee wildfire ($14.7 million) and Hurricane Hermine ($13.5 million).

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td colspan="3">At December 31,</td></tr><tr><td>(Dollars in thousands)</td><td>2017</td><td>2016</td><td>2015</td></tr><tr><td>Balance at beginning of year</td><td>$55,074</td><td>$58,910</td><td>$59,820</td></tr><tr><td>Liabilities assumed</td><td>115</td><td>175</td><td>315</td></tr><tr><td>Adjustments to reserves</td><td>-437</td><td>303</td><td>2,310</td></tr><tr><td>Benefits paid in the current year</td><td>-3,738</td><td>-4,315</td><td>-3,535</td></tr><tr><td>Balance at end of year</td><td>$51,014</td><td>$55,074</td><td>$58,910</td></tr><tr><td>(Some amounts may not reconcile due to rounding.)</td><td></td><td></td><td></td></tr></table>
<table><tr><td>2018</td><td>$16,990</td></tr><tr><td>2019</td><td>17,964</td></tr><tr><td>2020</td><td>17,115</td></tr><tr><td>2021</td><td>8,035</td></tr><tr><td>2022</td><td>7,669</td></tr><tr><td>Thereafter</td><td>24,668</td></tr><tr><td>Net commitments</td><td>$92,440</td></tr><tr><td>(Some amounts may not reconcile due to rounding.)</td><td></td></tr></table>
<table><tr><td></td><td colspan="9">Years Ended December 31,</td></tr><tr><td>(Dollars in millions)</td><td>Current Year</td><td colspan="2">Ratio %/ Pt Change</td><td>Prior Years</td><td colspan="2">Ratio %/ Pt Change</td><td>Total Incurred</td><td colspan="2">Ratio %/ Pt Change</td></tr><tr><td>2017</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Attritional</td><td>$1,103.7</td><td>50.6%</td><td></td><td>$-165.5</td><td>-7.5%</td><td></td><td>$938.3</td><td>43.1%</td><td></td></tr><tr><td>Catastrophes</td><td>715.7</td><td>32.8%</td><td></td><td>-21.2</td><td>-1.0%</td><td></td><td>694.5</td><td>31.8%</td><td></td></tr><tr><td>Total segment</td><td>$1,819.4</td><td>83.4%</td><td></td><td>$-186.6</td><td>-8.5%</td><td></td><td>$1,632.8</td><td>74.9%</td><td></td></tr><tr><td>2016</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Attritional</td><td>$1,096.0</td><td>52.9%</td><td></td><td>$-126.4</td><td>-6.1%</td><td></td><td>$969.7</td><td>46.8%</td><td></td></tr><tr><td>Catastrophes</td><td>134.1</td><td>6.5%</td><td></td><td>-35.3</td><td>-1.7%</td><td></td><td>98.8</td><td>4.8%</td><td></td></tr><tr><td>Total segment</td><td>$1,230.1</td><td>59.4%</td><td></td><td>$-161.6</td><td>-7.8%</td><td></td><td>$1,068.5</td><td>51.6%</td><td></td></tr><tr><td>2015</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Attritional</td><td>$940.6</td><td>48.2%</td><td></td><td>$-123.1</td><td>-6.3%</td><td></td><td>$817.5</td><td>41.9%</td><td></td></tr><tr><td>Catastrophes</td><td>16.7</td><td>0.9%</td><td></td><td>-9.2</td><td>-0.5%</td><td></td><td>7.6</td><td>0.4%</td><td></td></tr><tr><td>Total segment</td><td>$957.4</td><td>49.1%</td><td></td><td>$-132.3</td><td>-6.8%</td><td></td><td>$825.1</td><td>42.3%</td><td></td></tr><tr><td>Variance 2017/2016</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Attritional</td><td>$7.7</td><td>-2.3</td><td>pts</td><td>$-39.1</td><td>-1.4</td><td>pts</td><td>$-31.4</td><td>-3.7</td><td>pts</td></tr><tr><td>Catastrophes</td><td>581.6</td><td>26.3</td><td>pts</td><td>14.1</td><td>0.7</td><td>pts</td><td>595.7</td><td>27.0</td><td>pts</td></tr><tr><td>Total segment</td><td>$589.3</td><td>24.0</td><td>pts</td><td>$-25.1</td><td>-0.7</td><td>pts</td><td>$564.3</td><td>23.3</td><td>pts</td></tr><tr><td>Variance 2016/2015</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Attritional</td><td>$155.4</td><td>4.7</td><td>pts</td><td>$-3.3</td><td>0.2</td><td>pts</td><td>$152.2</td><td>4.9</td><td>pts</td></tr><tr><td>Catastrophes</td><td>117.4</td><td>5.6</td><td>pts</td><td>-26.1</td><td>-1.2</td><td>pts</td><td>91.2</td><td>4.4</td><td>pts</td></tr><tr><td>Total segment</td><td>$272.8</td><td>10.3</td><td>pts</td><td>$-29.4</td><td>-1.0</td><td>pts</td><td>$243.4</td><td>9.3</td><td>pts</td></tr><tr><td colspan="2">(Some amounts may not reconcile due to rounding.)</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr></table>

Question: What is the sum of Adjustments to reserves of At December 31, 2015, and Attritional of Years Ended December 31, Current Year ?
Answer: 3413.7
Reasoning program: add(2310.0,1103.7)