pre_text: estimated future pension benefit payments for the next ten years under the plan ( in millions ) are as follows : estimated future payments: .
post_text: bfi post retirement healthcare plan we acquired obligations under the bfi post retirement healthcare plan as part of our acquisition of allied . this plan provides continued medical coverage for certain former employees following their retirement , including some employees subject to collective bargaining agreements . eligibility for this plan is limited to certain of those employees who had ten or more years of service and were age 55 or older as of december 31 , 1998 , and certain employees in california who were hired on or before december 31 , 2005 and who retire on or after age 55 with at least thirty years of service . liabilities acquired for this plan were $ 1.2 million and $ 1.3 million , respectively , at the acquisition date and at december 31 , 2008 . multi-employer pension plans we contribute to 25 multi-employer pension plans under collective bargaining agreements covering union- represented employees . we acquired responsibility for contributions for a portion of these plans as part of our acquisition of allied . approximately 22% ( 22 % ) of our total current employees are participants in such multi- employer plans . these plans generally provide retirement benefits to participants based on their service to contributing employers . we do not administer these multi-employer plans . in general , these plans are managed by a board of trustees with the unions appointing certain trustees and other contributing employers of the plan appointing certain members . we generally are not represented on the board of trustees . we do not have current plan financial information from the plans 2019 administrators , but based on the information available to us , it is possible that some of the multi-employer plans to which we contribute may be underfunded . the pension protection act , enacted in august 2006 , requires underfunded pension plans to improve their funding ratios within prescribed intervals based on the level of their underfunding . until the plan trustees develop the funding improvement plans or rehabilitation plans as required by the pension protection act , we are unable to determine the amount of assessments we may be subject to , if any . accordingly , we cannot determine at this time the impact that the pension protection act may have on our consolidated financial position , results of operations or cash flows . furthermore , under current law regarding multi-employer benefit plans , a plan 2019s termination , our voluntary withdrawal , or the mass withdrawal of all contributing employers from any under-funded , multi-employer pension plan would require us to make payments to the plan for our proportionate share of the multi- employer plan 2019s unfunded vested liabilities . it is possible that there may be a mass withdrawal of employers contributing to these plans or plans may terminate in the near future . we could have adjustments to our estimates for these matters in the near term that could have a material effect on our consolidated financial condition , results of operations or cash flows . our pension expense for multi-employer plans was $ 21.8 million , $ 18.9 million and $ 17.3 million for the years ended december 31 , 2008 , 2007 and 2006 , respectively . republic services , inc . and subsidiaries notes to consolidated financial statements %%transmsg*** transmitting job : p14076 pcn : 133000000 ***%%pcmsg|131 |00027|yes|no|02/28/2009 21:12|0|0|page is valid , no graphics -- color : d| .
table: 2009 $14.9
table: 2010 15.9
table: 2011 16.2
table: 2012 19.2
table: 2013 21.9
table: 2014 through 2018 142.2
question: Analyse this data from a financial earnings document. what was the percent of the estimated future pension benefit payments increase from 2011 to 2012