I'm a little suspicious of the methodology here. First, going by charitable contributions stated on income tax returns is tricky. a lot of people give without deducting it. Second, this appears to include church giving. When you talk about charitable giving I think church giving skews things a bit. I understand that it qualifies as charitable giving, but I think for purposes of this conversation it should be segregated.
I'm not sure where Wisconsin ranks but I don't believe this measure is valid.