"Polls in Islamic countries where it's OK to ask such questions yield a figure of over 80%"
Where do you get this stuff? Who's doing the polling? Are they being asked by radical fundamentalists in front of their neighbors? I'd like to see the sources of your polls and figures.
I converted to follow Christ because I believe him to be who he said he is, because I need a gracious Savior, because there's no salvation apart from him, because I need his Holy Spirit to help me follow him.
This isn't a rhetorical question: why did you convert to Islam?