BTW – In the regex of the OP:

s/^\d\d//g;

The  /g regex modifier is pointless because the pattern is anchored at the start of the string, and there is never more than one of those.

However, if the  /m modifier were used to allow  ^ to match after embedded newlines,  /g might make some sense.

See discussions of g and m regex Modifiers in perlre and perlretut.

Update: Slight wording changes.