Following the controversy surrounding Mozilla’s (now former) CEO Brendan Eich and his $1000 donation in support of California’s Proposition 8 back in 2008, statistician Nate Silver looked at just how rare such anti-gay donations are in Silicon Valley.

In total between these 11 [Silicon Valley-based Fortune 500] companies, 83 percent of employee donations were in opposition to Proposition 8. So Eich was in a 17 percent minority relative to the top companies in Silicon Valley.

However, there was quite a bit of variation from business to business. At Intel, 60 percent of employee donations were in support of Proposition 8. By contrast, at Apple, 94 percent of employee donations were made in opposition to Proposition 8. The opposition was even higher at Google, where 96 percent of employee donations were against it, including $100,000 from co-founder Sergey Brin.

There isn’t much data on Mozilla. Only four Proposition 8 donors listed it as their employer: Eich, who donated in support of the measure, and three others who opposed it. But it’s likely that employee sentiment at Mozilla is much like that at Google. The organizations share a lot in common; Google accounts for a large share of Mozilla’s revenue, and both are based in Mountain View, Calif. Mozilla has a reputation for progressivity, and almost all donations by its employees during the 2012 election cycle were to liberal or libertarian candidates and causes.

Silver notes, however, that these figures only reflect employees who were willing to donate publicly, for or against Proposition 8.