{"pre_text": ["the following tables present a reconciliation of the beginning and ending balances of the fair value measurements using significant unobservable inputs ( level 3 ) for 2017 and 2016 , respectively: ."], "post_text": ["purchases , issuances and settlements , net .", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", "( 4 ) balance as of december 31 , 2016 .", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", ".", "$ 140 the company 2019s postretirement benefit plans have different levels of funded status and the assets are held under various trusts .", "the investments and risk mitigation strategies for the plans are tailored specifically for each trust .", "in setting new strategic asset mixes , consideration is given to the likelihood that the selected asset allocation will effectively fund the projected plan liabilities and meet the risk tolerance criteria of the company .", "the company periodically updates the long-term , strategic asset allocations for these plans through asset liability studies and uses various analytics to determine the optimal asset allocation .", "considerations include plan liability characteristics , liquidity needs , funding requirements , expected rates of return and the distribution of returns .", "strategies to address the goal of ensuring sufficient assets to pay benefits include target allocations to a broad array of asset classes and , within asset classes , strategies are employed to provide adequate returns , diversification and liquidity .", "in 2012 , the company implemented a de-risking strategy for the american water pension plan after conducting an asset-liability study to reduce the volatility of the funded status of the plan .", "as part of the de-risking strategy , the company revised the asset allocations to increase the matching characteristics of fixed-income assets relative to liabilities .", "the fixed income portion of the portfolio was designed to match the bond-like and long-dated nature of the postretirement liabilities .", "in 2017 , the company further increased its exposure to liability-driven investing and increased its fixed-income allocation to 50% ( 50 % ) , up from 40% ( 40 % ) , in an effort to further decrease the funded status volatility of the plan and hedge the portfolio from movements in interest rates .", "in 2012 , the company also implemented a de-risking strategy for the medical bargaining trust within the plan to minimize volatility .", "in 2017 , the company conducted a new asset-liability study that indicated medical trend inflation that outpaced the consumer price index by more than 2% ( 2 % ) for the last 20 years .", "given continuously rising medical costs , the company decided to increase the equity exposure of the portfolio to 30% ( 30 % ) , up from 20% ( 20 % ) , while reducing the fixed-income portion of the portfolio from 80% ( 80 % ) to 70% ( 70 % ) .", "the company also conducted an asset-liability study for the post-retirement non-bargaining medical plan .", "its allocation was adjusted to make it more conservative , reducing the equity allocation from 70% ( 70 % ) to 60% ( 60 % ) and increasing the fixed- income allocation from 30% ( 30 % ) to 40% ( 40 % ) .", "the post-retirement medical non-bargaining plan 2019s equity allocation was reduced due to the cap on benefits for some non-union participants and resultant reduction in the plan 2019s liabilities .", "these changes will take place in 2018 .", "the company engages third party investment managers for all invested assets .", "managers are not permitted to invest outside of the asset class ( e.g .", "fixed income , equity , alternatives ) or strategy for which they have been appointed .", "investment management agreements and recurring performance and attribution analysis are used as tools to ensure investment managers invest solely within the investment strategy they have been provided .", "futures and options may be used to adjust portfolio duration to align with a plan 2019s targeted investment policy. ."], "table": [["", "level 3"], ["balance as of january 1 2017", "$ 140"], ["actual return on assets", "2"], ["purchases issuances and settlements net", "136"], ["balance as of december 31 2017", "$ 278"]], "table_ori": [["", "Level 3"], ["Balance as of January 1, 2017", "$140"], ["Actual return on assets", "2"], ["Purchases, issuances and settlements, net", "136"], ["Balance as of December 31, 2017", "$278"]]}

Question: by how much did the balance increase from the beginning of 2017 to the end?
Evidence:
table_1: the balance as of january 1 2017 of level 3 is $ 140 ;
table_4: the balance as of december 31 2017 of level 3 is $ 278 ;
Program: subtract(278, 140), divide(#0, 140)
Answer:
str_answer: 98.57%
exe_answer: 0.98571