There’s no doubt trans visibility and rights have been on the rise, and new data from the Human Rights Campaign illustrates how dramatically some of the nation’s leading corporations have reflected that, adopting more inclusive policies and benefits for their employees. The results are helpful to LGBTQ workers looking for a seemingly safe employer, but they may not also reflect reality for the most marginalized people within the community.

The Corporate Equality Index is compiled by the HRC each year to analyze how well—or poorly—Fortune 500 companies accommodate LGBTQ workers. In this year’s index, 91 percent of Fortune 500 companies have nondiscrimination policies with protections for trans workers. The companies surveyed in the CEI, include “Fortune magazine’s 500 largest publicly traded businesses, American Lawyer magazine’s top 200 revenue-grossing law firms and hundreds of publicly and privately held mid- to large-sized businesses.” Among them, 89 percent offer transgender-inclusive health care coverage, and the vast majority have “eliminated exclusions,” altogether, meaning a greater number of procedures are covered.

These are undeniably significant improvements—a decade ago, only 9 percent of the corporations in the CEI provided trans health care. But trans people remain disproportionately unemployed and underemployed, facing wildly disproportionate rates of discrimination than the general public. So why the disparity?

In 2015, Fortune’s Claire Zillman wrote of the Fortune 500’s “quiet transgender revolution,” where, “for more than a decade,” the top corporations in the country had been implementing trans-inclusive policies despite a lack of social and governmental support for the trans community. Ginger Chien, an employee of AT&T, said she found internal resources to help her transition at the company in 2011. It was, “a life-changer,” she said.

Still, progress made by upper crust corporations like AT&T isn’t matched by most state governments, nor the federal government at all. Trans Americans have an unemployment rate three times that of other Americans, despite the “transgender revolution,” taking place in big business.

The United States Transgender Survey, produced by the National Center for Transgender Equality in 2015, remains the largest survey of trans Americans ever conducted. “Thirty percent of respondents who had a job reported being fired, denied a promotion, or experiencing some other form of mistreatment in the workplace due to their gender identity,” according to the report. Nearly one-third of respondents were living in poverty and 15 percent said they were unemployed, which was triple the national unemployment rate when the report was created.

For trans people of color, the rate of poverty and unemployment is even worse. Twenty percent of trans people of color in the USTS reported being unemployed. And there is still no federal law explicitly prohibiting discrimination in the workplace on the basis of gender identity, with legal disagreement regarding whether or not trans people are covered under protections in Title VII of the Civil Rights Act, which prohibits discrimination at work on the basis of sex.

So while there is a lack of antidiscrimination protections for trans workers especially, there’s also not enough real data to show that the companies that do protect trans employees are actually employing them. In an email to VICE, HRC press secretary Elliott Kozuch said the companies in the CEI collectively employ, “nearly 30 million workers around the globe,” and estimated that “roughly 30,000 to 90,000 transgender workers [are] operating under inclusive non-discrimination policies.” But those figures are ultimately incalculable.

Kozuch explained that the HRC is “not able to calculate a wholly accurate number,” due to a lack of available information aside from a 2012 estimate by the Williams Institute, an LGBTQ think tank at UCLA. And of course, there is no federal data collected about trans people in the workforce. “This rough estimate is the closest possible information we are able to provide, given the limits of data collection.”

“The number of transgender employees at Fortune 500 companies is not sufficiently tracked,” according to a statement from the National Center for Transgender Equality. “The EEOC requires companies to track how many male versus female employees they have,” but not transgender, and without that information, all we know is that enormously profitable conglomerates have made their working conditions more hospitable to the trans people who work there.

Mary Ann Horton’s 1997 lawsuit against her employer, now-defunct Lucent Technologies, secured non-discrimination protections for transgender employees, marking a groundbreaking moment for transgender workplace rights. Horton told Fortune in 2015, “Once a Fortune 500 pledged not to discriminate, I thought maybe some other companies might want to do that too… So I started waving the flag in the trans community, encouraging others to bring it up.” By 2002, when the HRC started to issue its annual report, other major companies began to institute similar changes.

Since then, the increase in trans-friendly internal policies has grown, benefiting the trans people who can secure gainful employment at one of these corporations. Transgender visibility may have incentivized companies to signal support to trans employees, but an internal policy change is an easy fix. Correcting the wildly high rates of discrimination, unemployment, and poverty impacting trans communities, particularly trans communities of color, is another issue altogether. Today, it is impossible to say how many trans people have actually benefited from these policies, or how beneficial they are to the most vulnerable members of the trans population.