part i item 1 . business our company founded in 1886 , american water works company , inc . ( the 201ccompany 201d or 201camerican water 201d ) is a holding company incorporated in delaware . american water is the largest and most geographically diverse investor owned publicly-traded united states water and wastewater utility company , as measured by both operating revenues and population served . we employ approximately 6700 professionals who provide drinking water , wastewater and other related services to an estimated 15 million people in 47 states , the district of columbia and ontario , canada . operating segments we conduct our business primarily through our regulated businesses segment . we also operate several market-based businesses that provide a broad range of related and complementary water and wastewater services , which include four operating segments that individually do not meet the criteria of a reportable segment in accordance with generally accepted accounting principles in the united states ( 201cgaap 201d ) . these four non- reportable operating segments are collectively presented as our 201cmarket-based businesses , 201d which is consistent with how management assesses the results of these businesses . additional information can be found in item 7 2014management 2019s discussion and analysis of financial condition and results of operations and note 19 2014segment information in the notes to consolidated financial statements . regulated businesses our primary business involves the ownership of subsidiaries that provide water and wastewater utility services to residential , commercial , industrial and other customers , including sale for resale and public authority customers . our subsidiaries that provide these services operate in approximately 1600 communities in 16 states in the united states and are generally subject to regulation by certain state commissions or other entities engaged in utility regulation , referred to as public utility commissions or ( 201cpucs 201d ) . the federal and state governments also regulate environmental , health and safety , and water quality matters . we report the results of the services provided by our utilities in our regulated businesses segment . our regulated businesses segment 2019s operating revenues were $ 2743 million for 2015 , $ 2674 million for 2014 and $ 2594 million for 2013 , accounting for 86.8% ( 86.8 % ) , 88.8% ( 88.8 % ) and 90.1% ( 90.1 % ) , respectively , of total operating revenues for the same periods . the following table summarizes our regulated businesses 2019 operating revenues , number of customers and estimated population served by state , each as of december 31 , 2015 : operating revenues ( in millions ) % (  % ) of total number of customers % (  % ) of total estimated population served ( in millions ) % (  % ) of total .
what is the approximate customer penetration in the west virginia market area?
( a ) includes illinois-american water company and american lake water company . ( b ) includes west virginia-american water company and its subsidiary bluefield valley water works company . ( c ) includes data from our utilities in the following states : georgia , hawaii , iowa , kentucky , maryland , michigan , new york , tennessee and virginia. .