local union and CTA: 71.9%
Note that that means that over 28% of my state and local union dues are not related to anything that the "impartial" arbitrator can justify making me pay for, and 64% of the national union dues are for non-chargeable activities (read, Democratic/progressive/liberal politics).
Always remember--liberals love compulsion. It's who they are, it's what they do. They enjoy making me pay for a union I don't want to support. So I get back the non-chargeable fees after jumping through their hoops, but I don't want to associate with them at all. Force, compulsion, and groupthink--that's what you get with unions.