Cleveland voter registration numbers

I don't know what to make of these registration numbers in Cleveland. I do know that there was a gap of 177,000 between Gore and Bush totals in 2000, and that Cleveland has at least 244,000 people over eighteen who did not vote for president in the last election. Assuming those voters vote in the same proportions as other Clevelanders, we would need to get all of them to the polls in order to tip the balance.