Is there a better way to track specific downloads?

In my website I have a lot of files to download and I want to track them by code words (for example, know the number of downloads of files that have the word “service” in the name).

What I’ve done is create triggers for certain words and tags asociated to every one of the triggers organized by category showing the URL of the file. This works perfect to see the number of downloads of each “code word” files and the number of downloads of both the category and the individual files. This looks something like this:

    Downloads of Service                 1500
      Service_file_1                      345
      Service_file_2                      120
      Service_file_3                       99

    Downloads of Documentation        300
      Documentation_file_1             40
      Documentation_file_2             23

The problem is that if, for ejample, I want to change the name of the category from “Downloads of Service” to “Service Downloads” all the data that’s been registered is lost since the tracking will start new in the “Service Downloads” category.

I don’t know if I explained this too well, but I’d love to know if there are better ways to do this.
Thank you.

Maybe this topic can be put into Tag Manager forum.
BTW maybe you can invalidate past reports, then recalculate them (if you still have visitor log).

yep I should have asked this in the Tag Manager forum, how can I change the category?