Once again, the country's biggest law firms outperformed corporate America in their level of support for lesbian, gay, bisexual, transgender and queer employees.

However, the number of firms receiving perfect scores in Human Rights Campaign Foundation's 2019 Corporate Equality Index, released Thursday, dropped from the 2018 peak. Of 164 firms participating, 114 received perfect scores. In the 2018 report, 127 of 160 participants earned the highest possible rating.

Still, this was enough to place the firms above every other industry tracked by the HRC.

“The highly competitive legal field continues to be the sector with the largest number of top-rated employers in the Corporate Equality Index,” Beck Bailey, acting director of the HRC Foundation's Workplace Equality Program, said in a statement. “Law firm leaders know that LGBTQ inclusion is absolutely essential in attracting and retaining top attorneys and staff.”

The number of firms receiving perfect scores had been steadily rising. The 2018 figure of 127 was a step up from 2017, which saw 112 perfect scores. That in turn was a rise from 95 in 2016 and 87 in 2015.

While 69.5 percent of the law firms participating received perfect scores for 2019, that figure outpaced the Fortune 500, where 55.7 percent of the companies participating earned scores of 100.

That number was also down in 2019, as 230 Fortune 500 companies received perfect scores in the previous year.

The survey, which is voluntary, evaluates the nation's largest companies and top-grossing law firms, the Am Law 100 and 200, in four areas: nondiscrimination policies based on sexual orientation, gender identity and expression; equitable benefits for LGBTQ workers and their families; supporting an inclusive culture and corporate social responsibility including public commitment to LGBTQ equality; and responsibility citizenship.

New criteria specifically introduced for 2019 look at whether companies and firms ensure full spousal and partner health care coverage parity, whether they affirm coverage for transition-related care and eliminate all so-called “transgender exclusions” from plans, and whether they ensure full LGBTQ inclusion in diverse supply chain programs.

In spite of the legal industry's apparent success in tackling inclusionary policies for the LGBTQ community, at least along the HRC's criteria, progress lags in other areas.

Among equity partnership ranks at the country's biggest firms in 2017, women made up 19 percent of the 31,658 total partners recorded, according to a National Law Journal survey. Meanwhile, the percentage of minority partners working in Am Law 200 firms and NLJ 250 firms increased just 0.5 percent in 2017, making up 9.1 percent of attorneys in Big Law, The American Lawyer reported last year.