In Perl, version numbers are really just strings. The string 1.10 would sort before 1.9 even though the version 1.10 comes after 1.9. You're kinda stuck, though, since you can't change the past.

The trick is to put in more decimal places, so version 1.9 is really 1.09 or 1.009, just like Perl 5.10 is really 5.010.