float division by zero bug.

[Nemiander]

Now there's this bug when using the group by: Grade, Kanji kentei level, JLPT level, Remembering the kanji. options without the add-on finding any kanji characters creating a float division by zero error. This can create confusion in users in what's wrong (example of me for awhile). Having a message pop up when it doesn't find any kanji would be good.

[vermouthmjl]

Hi @DuskitGalager
I fixed this error in a fork and shared it on the Anki website.
Feel free to take a look.
If you like the forked version, I'd really appreciate it if you could upvote it in the link above. It would make it easier to find for other people as well ^^
Thanks!