#!/usr/bin/perl 

use warnings;
use strict;

my %nums;
@nums{qw(today yesterday this last)} = undef;
my $alts = join('|',keys %nums);

while (<DATA>) {

    /($alts)(\d+)\1/;
    $nums{$1} = $2;

}

for my $key (keys %nums) {
    my $ans = ($nums{$key} * 0.4)/100;
    print "$key: $ans (from $nums{$key})\n"
}

__DATA__
Today: today408today
Clicks: 34
Yesterday: yesterday555yesterday
Clicks: 61
This Month: this11360this
Clicks: 812
Last Month: last5350last
Clicks: 454