my $i = 1;
for (qw/5p-tR-halves 5p-tRFs 3p-tR-halves 3p-CCA-tRFs 3p-tRFs tRF-1 tRNA-leader misc-tRFs/) {
    $->{$_} += $line[$i] / $reads * 1000000;
    $i += 2; # Odd entries only
}