pre_text: from those currently anticipated and expressed in such forward-looking statements as a result of a number of factors , including those we discuss under 201crisk factors 201d and elsewhere in this form 10-k . you should read 201crisk factors 201d and 201cforward-looking statements . 201d executive overview general american water works company , inc . ( herein referred to as 201camerican water 201d or the 201ccompany 201d ) is the largest investor-owned united states water and wastewater utility company , as measured both by operating revenues and population served . our approximately 6400 employees provide drinking water , wastewater and other water related services to an estimated 15 million people in 47 states and in one canadian province . our primary business involves the ownership of water and wastewater utilities that provide water and wastewater services to residential , commercial , industrial and other customers . our regulated businesses that provide these services are generally subject to economic regulation by state regulatory agencies in the states in which they operate . the federal government and the states also regulate environmental , health and safety and water quality matters . our regulated businesses provide services in 16 states and serve approximately 3.2 million customers based on the number of active service connections to our water and wastewater networks . we report the results of these businesses in our regulated businesses segment . we also provide services that are not subject to economic regulation by state regulatory agencies . we report the results of these businesses in our market-based operations segment . in 2014 , we continued the execution of our strategic goals . our commitment to growth through investment in our regulated infrastructure and expansion of our regulated customer base and our market-based operations , combined with operational excellence led to continued improvement in regulated operating efficiency , improved performance of our market-based operations , and enabled us to provide increased value to our customers and investors . during the year , we focused on growth , addressed regulatory lag , made more efficient use of capital and improved our regulated operation and maintenance ( 201co&m 201d ) efficiency ratio . 2014 financial results for the year ended december 31 , 2014 , we continued to increase net income , while making significant capital investment in our infrastructure and implementing operational efficiency improvements to keep customer rates affordable . highlights of our 2014 operating results compared to 2013 and 2012 include: .
post_text: continuing operations income from continuing operations included 4 cents per diluted share of costs resulting from the freedom industries chemical spill in west virginia in 2014 and included 14 cents per diluted share in 2013 related to a tender offer . earnings from continuing operations , adjusted for these two items , increased 10% ( 10 % ) , or 22 cents per share , mainly due to favorable operating results from our regulated businesses segment due to higher revenues and lower operating expenses , partially offset by higher depreciation expenses . also contributing to the overall increase in income from continuing operations was lower interest expense in 2014 compared to the same period in 2013. .
table: 2014 2013 2012
table: Income from continuing operations $2.39 $2.07 $2.10
table: Income (loss) from discontinued operations, net of tax $(0.04) $(0.01) $(0.09)
table: Diluted earnings per share $2.35 $2.06 $2.01
question: Analyse this data from a financial earnings document. by how much did income from continuing operations increase from 2012 to 2014?