american tower corporation and subsidiaries notes to consolidated financial statements 2014 ( continued ) at december 31 , 2005 , the company had net federal and state operating loss carryforwards available to reduce future taxable income of approximately $ 2.2 billion and $ 2.4 billion , respectively . if not utilized , the company 2019s net operating loss carryforwards expire as follows ( in thousands ) : . 
|Years ended December 31,|Federal|State|
|2006 to 2010|$5,248|$469,747|
|2011 to 2015|10,012|272,662|
|2016 to 2020|397,691|777,707|
|2021 to 2025|1,744,552|897,896|
|Total|$2,157,503|$2,418,012|
 sfas no . 109 , 201caccounting for income taxes , 201d requires that companies record a valuation allowance when it is 201cmore likely than not that some portion or all of the deferred tax assets will not be realized . 201d at december 31 , 2005 , the company has provided a valuation allowance of approximately $ 422.4 million , including approximately $ 249.5 million attributable to spectrasite , primarily related to net operating loss and capital loss carryforwards . approximately $ 237.8 million of the spectrasite valuation allowance was assumed as of the acquisition date . the balance of the valuation allowance primarily relates to net state deferred tax assets . the company has not provided a valuation allowance for the remaining deferred tax assets , primarily its federal net operating loss carryforwards , as management believes the company will have sufficient time to realize these federal net operating loss carryforwards during the twenty-year tax carryforward period . the company intends to recover a portion of its deferred tax asset through its federal income tax refund claims related to the carry back of certain federal net operating losses . in june 2003 and october 2003 , the company filed federal income tax refund claims with the irs relating to the carry back of $ 380.0 million of net operating losses generated prior to 2003 , of which the company initially anticipated receiving approximately $ 90.0 million . based on preliminary discussions with tax authorities , the company has revised its estimate of the net realizable value of the federal income tax refund claims and anticipates receiving a refund of approximately $ 65.0 million as a result of these claims by the end of 2006 . there can be no assurances , however , with respect to the specific amount and timing of any refund . the recoverability of the company 2019s remaining net deferred tax asset has been assessed utilizing stable state ( no growth ) projections based on its current operations . the projections show a significant decrease in depreciation and interest expense in the later years of the carryforward period as a result of a significant portion of its assets being fully depreciated during the first fifteen years of the carryforward period and debt repayments reducing interest expense . accordingly , the recoverability of the net deferred tax asset is not dependent on material improvements to operations , material asset sales or other non-routine transactions . based on its current outlook of future taxable income during the carryforward period , management believes that the net deferred tax asset will be realized . the realization of the company 2019s deferred tax assets as of december 31 , 2005 will be dependent upon its ability to generate approximately $ 1.3 billion in taxable income from january 1 , 2006 to december 31 , 2025 . if the company is unable to generate sufficient taxable income in the future , or carry back losses , as described above , it will be required to reduce its net deferred tax asset through a charge to income tax expense , which would result in a corresponding decrease in stockholders 2019 equity . from time to time the company is subject to examination by various tax authorities in jurisdictions in which the company has significant business operations . the company regularly assesses the likelihood of additional assessments in each of the tax jurisdictions resulting from these examinations . during the year ended .


Question: in 2005 what was the percentage of the federal nol set to expire between 2016 to 2020 (in percentage)

Solution:
def solution():
    # Define variables name and value
    federal_nol_2016_to_2020 = 397691
    total_federal_nol = 2157503
    
    # Do math calculation to get the answer
    answer = (federal_nol_2016_to_2020 / total_federal_nol) * 100
    
    return answer

Answer: 18.432929177850507