19.75 after a few attempts :)
It would be nice to have a reset button. Sometimes I get stuck in the first 10 numbers and it's obvious I'll get an horrible time, so I'd like to start again immediately.
Edit: Perhaps after some time like 1.5 seconds, highlight the next number so it's easier to find. I will not help too much to get a record, but it will reduce how annoying is to get stuck.