In reading the numbers back, they are being rounded to 18 decimal digits of precision:

use warnings;

for(10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9) {
  printf "%.18g\n", $_;
}

__END__
Outputs:

10.0999999999999996
10.1999999999999993
10.3000000000000007
10.4000000000000004
10.5
10.5999999999999996
10.6999999999999993
10.8000000000000007
10.9000000000000004
[download]

I don't know why that is happening or how to influence the result, but you clearly want those numbers to be rounded to 3 decimal digits of precision:

use warnings;

for(10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9) {
  printf "%.3g\n", $_;
}

__END__
Outputs:

10.1
10.2
10.3
10.4
10.5
10.6
10.7
10.8
10.9
[download]

Cheers,
Rob