my @dateParts = split /[\/\-]/, $chaseList[1];
my $month = $dateParts[0];    # For purposes of example; see note below

##</code><code>##

    $vendor = $chaseList[2];
    $amount = $chaseList[3];
    # Now we can directly reference the hash by vendor inside the array by month number:
    # $chaseArray[$month]{$vendor}

##</code><code>##

    my (
        $tranType, 
        $tranDate, 
        $tranDesc, 
        $tranAmount, 
        $tranMedium, 
        @extraStuffJustInCase
    ) = split /\,/, @chaseList;
    my ($tranVendor, @restOfDesc) = split /\s/, $tranDesc;

##</code><code>##

    $chaseArray[$month]{$tranVendor} += $tranAmount;