There are more than 1.3 million active charities working in the country’s nonprofit sector, and of those charities, a mere 3.3% focus on women’s causes. Less than that, though, is the amount of charitable giving received by these organizations.

According to the Women’s Philanthropy Institute, the 45,000 charities dedicated largely to women’s causes or that are female-led collectives trying to make change received $6.3 billion between 2012 and 2015. From a different perspective, that’s just 1.6% of all charitable giving.

The Women’s Philanthropy Institute came to the conclusion after launching the Women and Girls Index, a public database of the country’s charities focusing on women’s causes, Fast Company reported. To build the database, the institute analyzed available public 990 tax filings by group name, mission statement and program descriptions.

Of those charities, organizations dedicated to women’s health received the most amount of funding. However, due to the small slice of overall donations received by nonprofits supporting women and girls, most remain small with limited operating costs and employees.

According to the study, human services groups make up the biggest portion of recipients at 35%. That’s followed by groups dedicated to mutual, public and societal benefit at 23%. Arts and cultural groups place third at 13% of the total potential beneficiaries, with female-focused health and education operations behind that.

Read the full report online.