westrock company notes to consolidated financial statements fffd ( continued ) a reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows ( in millions ) : .
by what percent did the balance of tax benefits increase between the beginning of 2016 and the end of 2018?
( 1 ) amounts in fiscal 2018 and 2017 relate to the mps acquisition . adjustments in fiscal 2016 relate to the combination and the sp fiber acquisition . ( 2 ) amounts in fiscal 2018 relate to the settlement of state audit examinations and federal and state amended returns filed related to affirmative adjustments for which a there was a reserve . amounts in fiscal 2017 relate to the settlement of federal and state audit examinations with taxing authorities . as of september 30 , 2018 and 2017 , the total amount of unrecognized tax benefits was approximately $ 127.1 million and $ 148.9 million , respectively , exclusive of interest and penalties . of these balances , as of september 30 , 2018 and 2017 , if we were to prevail on all unrecognized tax benefits recorded , approximately $ 108.7 million and $ 138.0 million , respectively , would benefit the effective tax rate . we regularly evaluate , assess and adjust the related liabilities in light of changing facts and circumstances , which could cause the effective tax rate to fluctuate from period to period . we recognize estimated interest and penalties related to unrecognized tax benefits in income tax expense in the consolidated statements of operations . as of september 30 , 2018 , we had liabilities of $ 70.4 million related to estimated interest and penalties for unrecognized tax benefits . as of september 30 , 2017 , we had liabilities of $ 81.7 million , net of indirect benefits , related to estimated interest and penalties for unrecognized tax benefits . our results of operations for the fiscal year ended september 30 , 2018 , 2017 and 2016 include expense of $ 5.8 million , $ 7.4 million and $ 2.9 million , respectively , net of indirect benefits , related to estimated interest and penalties with respect to the liability for unrecognized tax benefits . as of september 30 , 2018 , it is reasonably possible that our unrecognized tax benefits will decrease by up to $ 5.5 million in the next twelve months due to expiration of various statues of limitations and settlement of issues . we file federal , state and local income tax returns in the u.s . and various foreign jurisdictions . with few exceptions , we are no longer subject to u.s . federal and state and local income tax examinations by tax authorities for years prior to fiscal 2015 and fiscal 2008 , respectively . we are no longer subject to non-u.s . income tax examinations by tax authorities for years prior to fiscal 2011 , except for brazil for which we are not subject to tax examinations for years prior to 2005 . while we believe our tax positions are appropriate , they are subject to audit or other modifications and there can be no assurance that any modifications will not materially and adversely affect our results of operations , financial condition or cash flows . note 6 . segment information we report our financial results of operations in the following three reportable segments : corrugated packaging , which consists of our containerboard mill and corrugated packaging operations , as well as our recycling operations ; consumer packaging , which consists of consumer mills , folding carton , beverage , merchandising displays and partition operations ; and land and development , which sells real estate primarily in the charleston , sc region . following the combination and until the completion of the separation , our financial results of operations had a fourth reportable segment , specialty chemicals . prior to the hh&b sale , our consumer packaging segment included hh&b . certain income and expenses are not allocated to our segments and , thus , the information that .