The number of companies filing disclosure statements on climate change through CDP increased 36.5% between 2020 and 2021.

That’s the biggest one-year percentage increase since the not-for-profit charity started tracking roughly 20 years ago. For context, about 80% of the companies listed on the S&P 500 index disclose through CDP.

CDP runs what’s considered the most comprehensive global disclosure system for a range of entities, including companies and cities, to measure and manage their environmental impacts.

The topic is taking on renewed interest with the U.S. Securities and Exchange Commission, which is preparing a rule to require some level of disclosure regarding greenhouse gas emissions from companies’ businesses. The rule, initially expected last year, is now delayed until spring, according to The Wall Street Journal.