Financial report context:
the following table provides a summary of our historical capital expenditures related to the upgrading of our infrastructure and systems: .

Financial table:
( in millions ): transmission and distribution; for the years ended december 31 , 2018: $ 572; for the years ended december 31 , 2017: $ 551; for the years ended december 31 , 2016: $ 568
( in millions ): treatment and pumping; for the years ended december 31 , 2018: 231; for the years ended december 31 , 2017: 171; for the years ended december 31 , 2016: 151
( in millions ): services meter and fire hydrants; for the years ended december 31 , 2018: 303; for the years ended december 31 , 2017: 281; for the years ended december 31 , 2016: 297
( in millions ): general structure and equipment; for the years ended december 31 , 2018: 371; for the years ended december 31 , 2017: 281; for the years ended december 31 , 2016: 202
( in millions ): sources of supply; for the years ended december 31 , 2018: 26; for the years ended december 31 , 2017: 54; for the years ended december 31 , 2016: 59
( in millions ): wastewater; for the years ended december 31 , 2018: 83; for the years ended december 31 , 2017: 96; for the years ended december 31 , 2016: 34
( in millions ): total capital expenditures; for the years ended december 31 , 2018: $ 1586; for the years ended december 31 , 2017: $ 1434; for the years ended december 31 , 2016: $ 1311

Additional report context:
in 2018 , our capital expenditures increased $ 152 million , or 10.6% ( 10.6 % ) , primarily due to investment across the majority of our infrastructure categories . in 2017 , our capital expenditures increased $ 123 million , or 9.4% ( 9.4 % ) , primarily due to investment in our general structure and equipment and wastewater categories . we also grow our business primarily through acquisitions of water and wastewater systems , as well as other water-related services . these acquisitions are complementary to our existing business and support continued geographical diversification and growth of our operations . generally , acquisitions are funded initially with short- term debt , and later refinanced with the proceeds from long-term debt . the following is a summary of the acquisitions and dispositions affecting our cash flows from investing activities : 2022 the majority of cash paid for acquisitions pertained to the $ 365 million purchase of pivotal within our homeowner services group . 2022 paid $ 33 million for 15 water and wastewater systems , representing approximately 14000 customers . 2022 received $ 35 million for the sale of assets , including $ 27 million for the sale of the majority of the o&m contracts in our contract services group during the third quarter of 2018 . 2022 the majority of cash paid for acquisitions pertained to the $ 159 million purchase of the wastewater collection and treatment system assets of the municipal authority of the city of mckeesport , pennsylvania ( the 201cmckeesport system 201d ) , excluding a $ 5 million non-escrowed deposit made in 2016 . 2022 paid $ 18 million for 16 water and wastewater systems , excluding the mckeesport system and shorelands ( a stock-for-stock transaction ) , representing approximately 7000 customers . 2022 received $ 15 million for the sale of assets . 2022 paid $ 199 million for 15 water and wastewater systems , representing approximately 42000 customers . 2022 made a non-escrowed deposit of $ 5 million related to the mckeesport system acquisition . 2022 received $ 9 million for the sale of assets . as previously noted , we expect to invest between $ 8.0 billion to $ 8.6 billion from 2019 to 2023 , with $ 7.3 billion of this range for infrastructure improvements in our regulated businesses . in 2019 , we expect to .

Question: what percentage of total capital expenditures were related to transmission and distribution in 2018?
Answer: 36.1%