I don't know what the stats show, but from working in the nonprofit sector, a substantial portion of funds for nonprofit activity come from various levels of government. As you might imagine, this kind of funding is often more restrictive than other sources, like foundations, private donors, etc., which can handcuff some agencies from doing business in a way they believe to be most effective/efficient. While there are obvious benefits to that (there are certainly agencies that wastefully spend their grants and donations), it can also hamper progress and hamper an agencies reaction and response when needs change. Additionally, government funding often allows nonprofits to incorporate overhead in their grants (although it's usually very limited), so organizations can pay for their operations, which other sources of funding usually don't like to provide for (they want to see the funds go directly to helping x, y, or z without funding the staffing required to do so).
The point being, it's really amazing to see this kind of charitable giving in the private sector, as it really is needed. While I know their money will be given through foundations that place restrictions on how the funds will be used and require MOs and such, which is so important to ensure funds are spent wisely, they'll likely do so in a way that allows much more flexibility in how an agency can use those funds in creative ways to solve problems.