my $pErr = 5; # for plus/minus 5.
sub MakeP { my $p = $_[0]; $p -= $pErr; $p += int(rand() * 2 * ($pErr + 0.5)); return $p / 100 }

#Test
my @foo;
push @foo, MakeP( 50 ) for 0 .. 20000;
@foo = sort @foo;
while ( @foo )
{
    my $next = shift @foo;
    my $count = 1;
    while ( @foo and $foo[0] == $next ) {
        ++$count; shift @foo }
    printf "%f\t%6d\n", $next, $count;
}