1. California ($50.4 billion)
2. Iowa ($36.1 billion)
3. Nebraska ($33.4 billion)
4. Texas ($25.7 billion)
5. Minnesota ($23.8 billion)
6. Illinois ($21.9 billion)
7. North Carolina ($20.7 billion)
8. Wisconsin ($19.1 billion)
9. Kansas ($18.9 billion)
10. Washington ($17.2 billion)