IDACORP's 2019 fourth-quarter earnings per diluted share were $0.93, an increase of $0.41 per share over last year's fourth quarter.
IDACORP's earnings per diluted share for the full-year 2019 were $4.61, an increase of $0.12 per share over 2018.
IDACORP's cumulative average growth rate in diluted earnings per share is 7.9% since 2007.
Today, we also initiated our full-year 2020 IDACORP earnings guidance estimate to be in the range of $4.45 to $4.65 per diluted share with our expectation that Idaho Power will not need to utilize any of the tax credits in 2020 that are available to support earnings in Idaho under its settlement stipulation with the Idaho Public Utilities Commission.
Last week, we announced that after 24 years with the company that I would retire effective June 1 of this year.
She's an electrical engineer by training and she's got over 32 years of experience at Idaho Power.
Not only does she have a long tenure at the company, she also has a long history with Idaho Power as her grandfather was a lineman with the company for 30 years prior to Lisa joining the company.
She has contributed significantly to the operational and financial success of Idaho Power since becoming an officer in 2005.
Most Idaho Power customers experienced -- most Idaho customers experienced an overall price decrease for the second consecutive year in 2019 with business customers' rates going down by at least 5%.
Idaho Power kept customers' lights on 99.975% of the time in 2019, and overall system reliability was among the best in company history, finishing very close to 2018's record results.
For the third year in a row, Idaho remains the fastest-growing state in the nation, and Idaho Power's customer base grew 2.5% in 2019, including a 2.7% growth rate for our residential customer segment.
Idaho Power now has more than 570,000 customers, and we view the reliable, affordable, clean energy that our company provides as a key driver for continuing to attract new customers.
Moody's current forecast of GDP in Idaho Power's service area predicts growth of 4.4% in 2020 and another 4.4% in 2021.
Meanwhile, employment increased 3.2%, and the unemployment rate was 2.8% at the end of 2019, compared with 3.5% nationally.
Idaho Power's most recent integrated resource plan calls for continued work toward a unit-by-unit early exit from the Jim Bridger plant located in Wyoming by 2030.
In 2019, the company ended its participation in Unit 1 of the North Valmy plant in Nevada, which was a significant milestone in our path away from coal.
We also have an agreement to exit Unit 2 by 2025.
As recently as 2013, coal was our largest energy source at 47% of our total energy mix.
Today, that number is around 16%.
Our path away from coal, which is driven by the economics of the plant, aligns with our Clean Today, Cleaner Tomorrow plan to provide 100% clean energy by 2045.
The IRP we amended and filed at the end of last month also plans for us to include 120 megawatts of solar from the Jackpot Solar power purchase agreement.
We do not expect Idaho Power to file a general rate case in Idaho or Oregon in the next 12 months.
Strong net customer growth of 2.5% added $18.8 million to operating income in 2019.
A decline in usage per customer, mostly related to lower irrigation sales, decreased operating income by $21.4 million.
Greater precipitation and more moderate spring and summer temperatures led to 11% less use per customer for those in the agricultural irrigation class this year.
Further down the table, net retail revenues per megawatt hour decreased operating income by $2.8 million.
Idaho Power's open access transmission tariff rates declined by 10% in October of 2018 and again by 13% in October 2019, lowering transmission wheeling-related revenues by $5.3 million.
Next on the table, other operating and maintenance expenses decreased $8.7 million as our team's continued focus on cost management resulted in lower expenses across several areas.
Contributing to this decrease was lower bad debt expense of $1.1 million due to a strong economy and the nonrecurrence of a 2018 O&M expense of $4 million for a noncash amortization of regulatory deferrals related to tax reform.
Idaho Power's 2019 return on year-end equity in Idaho landed between the 9.5% tax credit support level and the 10% customer sharing line under the Idaho regulatory settlement stipulation.
Last year, we recorded a $5 million provision against revenues for sharing, which did not recur.
Idaho Power has the full $45 million of approved credits available to support earnings in future years.
As a reminder, the tax credit support line will be at 9.4% for 2020.
These items collectively resulted in a year-over-year increase to Idaho Power's operating income of $2.3 million.
Nonoperating income and expenses netted to a $9.9 million improvement to pre-tax earnings due to several items.
A $4.2 million charge in 2018 related to Idaho Power's post-retirement plan did not recur.
Next, our allowance for equity funds used during construction increased $2.7 million as the average construction work in progress balance was higher throughout 2019.
Finally, stronger asset returns this year led to $2.1 million of higher investment income from the Rabbi Trust associated with Idaho Power's nonqualified defined benefit pension plans.
On the next line, you will see income taxes were higher by $10.1 million.
Remember that 2018 included $5.7 million of benefits from remeasurement of deferred taxes at Idaho Power due to income tax reform, as well as $1.3 million of tax-deductible bond redemption costs incurred last year.
Finally, at IDACORP Financial Services, distributions from the sale of low-income housing properties led to approximately $3 million higher net income at that subsidiary.
Overall, Idaho Power's and IDACORP's net income were $2.1 million and $6.1 million higher than last year, respectively.
Regarding dividends, you'll note that in addition to the latest dividend increase of 6.3% announced by the board of directors last September, the board also increased IDACORP's target dividend payout ratio to 60% to 70% of sustainable earnings.
We expect to recommend an annual dividend increase of 5% or more to the board of directors in the coming year.
Cash flows from operations were $125 million lower than 2018.
We are initiating IDACORP's 2020 earnings guidance in the range of $4.45 to $4.65 per diluted share, which is up roughly 4% over prior-year guidance range and assumes no use of additional tax credits under normal weather conditions.
Our record 12 years of earnings growth is something that sets us apart from our peers.
We expect O&M expenses to be in the range of $350 million to $360 million, which would keep O&M relatively flat for the ninth straight year.
We expect capital expenditures will lift somewhat to the range of $300 million to $310 million.
You'll note that our updated five-year forecast of capital expenditures is also higher than our previous plan, now forecasted to range from $1.6 billion to $1.7 billion over that time.
Finally, our current reservoir storage and stream flow forecast suggests that hydropower generation should be in the range of 6.5 million to 8.5 million megawatt hours.
The latest projections from the National Oceanic and Atmospheric Administration suggests an equal chance of above or below normal precipitation levels and a 40% to 50% chance of above normal temperatures from March to May.

Summary:
IDACORP's 2019 fourth-quarter earnings per diluted share were $0.93, an increase of $0.41 per share over last year's fourth quarter.
Today, we also initiated our full-year 2020 IDACORP earnings guidance estimate to be in the range of $4.45 to $4.65 per diluted share with our expectation that Idaho Power will not need to utilize any of the tax credits in 2020 that are available to support earnings in Idaho under its settlement stipulation with the Idaho Public Utilities Commission.
We are initiating IDACORP's 2020 earnings guidance in the range of $4.45 to $4.65 per diluted share, which is up roughly 4% over prior-year guidance range and assumes no use of additional tax credits under normal weather conditions.