Replace "my @fields" onwards with this code:

my (undef,undef,@fields) = split(/\,/,shift @rows);
my %stats = ();
for my $r(@rows){
   my ($pxname,$svname,@values) = split /\,/,$r;
   for my $f(@fields){
     $stats{$pxname}{$svname}{$f} = shift @values;
   }
}
[download]

Note: This modifies both @rows, and @values - I'm assuming you don't need these after the info is extracted.