use strict;
use warnings;

my @lines = (
   "0|aa aa|1998|aaa a|a aaa|10|aa a aa",
   "1|bbb aa|1992|fa a|gaa|5|gfsa aa",
   "2|aa ba|1997|afa|hhaa|1|asdf aa",
   "3|cccaa|1997|ssa s|hhava|3|gfdh gaa",
   "4|adaa|1994|g a a|jiua|6|angf a"
);

my $field = 5;

@lines = 
   map { join '|', @$_ }
      sort { $b->[$field] <=> $a->[$field] }
         map { [ split /\|/ ] }
            @lines;

print "$_\n" for @lines;