While there aren’t consistent definitions around the inclusion of environmental, social and governance issues in investing, factoring them into the investment process is now mainstream, which is increasing the demand for ESG data, according to a report by capital markets consultancy firm Opimas.

Institutional investors, such as pension funds, insurers and asset managers, have been at the forefront of that demand, the report noted. In particular, major plans like Japan’s Government Pension Investment Fund and Europe’s Amundi are integrating ESG factors into their investment processes and applying proxy-voting practices. As a result, responsible investing has been on a major uptrend, increasing to $30 trillion assets under management in 2018 from $23 trillion in 2016. The report said it expects that number to rise to $35 trillion by 2020.

Read: Most Canadian institutional investors engaging in ESG issues: survey

Correspondingly, investors will be likely to spend more to acquire useful ESG data, according to the report. It estimated total ESG data spending, including relevant content and indices, reached $505 million in 2018. That’s predicted to rise to $745 million in 2020.

U.K.-based index provider FTSE Russell is amping up its capabilities in this area and recently partnered with ESG rating firm Sustainalytics. Together, the two firms plan to develop the FTSE Russell ESG indexes based on the existing Russell 1000, 2000 and 3000 indexes.

“This is an exciting development for our clients as it will provide new tools and benchmarks,” said Mark Makepeace, chief executive officer at FTSE Russell, in a statement announcing the partnership in December 2018. “FTSE Russell has been a leader in sustainable investment for nearly two decades and has been supporting the growing demand for ESG integration into passive strategies.

“The partnership with Sustainalytics enables us to provide a greater selection of options and choice to meet these ever-growing client demands.”

Read: A quarter of professionally managed U.S. AUM in ESG investments: survey