welltower inc .notes to consolidated financial statements is no longer present ( and additional weight may be given to subjective evidence such as our projections for growth ) .the valuation allowance rollforward is summarized as follows for the periods presented ( in thousands ) : year ended december 31 , 2017 2016 2015 .
[['2016', 'year ended december 31 2017 2016', 'year ended december 31 2017 2016', 'year ended december 31 2017'], ['beginning balance', '$ 96838', '$ 98966', '$ 85207'], ['expense ( benefit )', '30445', '-2128 ( 2128 )', '13759'], ['ending balance', '$ 127283', '$ 96838', '$ 98966']]
as a result of certain acquisitions , we are subject to corporate level taxes for any related asset dispositions that may occur during the five-year period immediately after such assets were owned by a c corporation ( 201cbuilt-in gains tax 201d ) .the amount of income potentially subject to this special corporate level tax is generally equal to the lesser of ( a ) the excess of the fair value of the asset over its adjusted tax basis as of the date it became a reit asset , or ( b ) the actual amount of gain .some but not all gains recognized during this period of time could be offset by available net operating losses and capital loss carryforwards .during the year ended december 31 , 2016 , we acquired certain additional assets with built-in gains as of the date of acquisition that could be subject to the built-in gains tax if disposed of prior to the expiration of the applicable ten-year period .we have not recorded a deferred tax liability as a result of the potential built-in gains tax based on our intentions with respect to such properties and available tax planning strategies .under the provisions of the reit investment diversification and empowerment act of 2007 ( 201cridea 201d ) , for taxable years beginning after july 30 , 2008 , the reit may lease 201cqualified health care properties 201d on an arm 2019s-length basis to a trs if the property is operated on behalf of such subsidiary by a person who qualifies as an 201celigible independent contractor . 201d generally , the rent received from the trs will meet the related party rent exception and will be treated as 201crents from real property . 201d a 201cqualified health care property 201d includes real property and any personal property that is , or is necessary or incidental to the use of , a hospital , nursing facility , assisted living facility , congregate care facility , qualified continuing care facility , or other licensed facility which extends medical or nursing or ancillary services to patients .we have entered into various joint ventures that were structured under ridea .resident level rents and related operating expenses for these facilities are reported in the consolidated financial statements and are subject to federal , state and foreign income taxes as the operations of such facilities are included in a trs .certain net operating loss carryforwards could be utilized to offset taxable income in future years .given the applicable statute of limitations , we generally are subject to audit by the internal revenue service ( 201cirs 201d ) for the year ended december 31 , 2014 and subsequent years .the statute of limitations may vary in the states in which we own properties or conduct business .we do not expect to be subject to audit by state taxing authorities for any year prior to the year ended december 31 , 2011 .we are also subject to audit by the canada revenue agency and provincial authorities generally for periods subsequent to may 2012 related to entities acquired or formed in connection with acquisitions , and by the u.k . 2019s hm revenue & customs for periods subsequent to august 2012 related to entities acquired or formed in connection with acquisitions .at december 31 , 2017 , we had a net operating loss ( 201cnol 201d ) carryforward related to the reit of $ 448475000 .due to our uncertainty regarding the realization of certain deferred tax assets , we have not recorded a deferred tax asset related to nols generated by the reit .these amounts can be used to offset future taxable income ( and/or taxable income for prior years if an audit determines that tax is owed ) , if any .the reit will be entitled to utilize nols and tax credit carryforwards only to the extent that reit taxable income exceeds our deduction for dividends paid .the nol carryforwards generated through december 31 , 2017 will expire through 2036 .beginning with tax years after december 31 , 2017 , the tax cuts and jobs act ( 201ctax act 201d ) eliminates the carryback period , limits the nols to 80% ( 80 % ) of taxable income and replaces the 20-year carryforward period with an indefinite carryforward period. .

Question: what is the percentage change in the balance valuation allowance rollforward during 2016?
Answer: -2.2%