I think the percentage would be low, maybe 10 percent if even that. A lot of people really don't care about those issues since it doesn't effect them personally. Many have too much invested in that organization and dont want to deal with the changes that leaving the organization involves. Many feel validated and have a since of belonging in that organization and they also have a social support group within it.
Unless they are severely and negatively impacted by something in the organization they aren't going anywhere.