Women may hold up “half the sky,” but giving to organizations dedicated to women and girls accounts for just 1.6% of all giving in the United States, according to a new study from the Women’s Philanthropy Institute.

The study’s authors combed through the mission statements of more than 1 million charitable organizations to assemble the Women & Girls Index, the first census of US-based nonprofits that focus on women and girls. Their search uncovered 45,000 organizations that either serve primarily women and girls or are collectives of women and girls serving general philanthropic purposes. Together, these 45,000 organizations made up 3.3% of nonprofits in the United States and received a total of $6.3 billion in charitable giving in 2016. In comparison, religious institutions–the largest philanthropic subsector–received $123.8 billion in giving.

The researchers also found that women’s and girls’ organizations are significantly smaller, on average, than other nonprofits when assessed in terms of budget, assets, and staff. “As a whole,” they conclude, “organizations dedicated to women and girls appear to be doing more with less.”

To read the full report, “The Women & Girls Index: Measuring Giving to Women’s and Girls’ Causes,” click here.