Where do you get your stats? Honestly, I always see it written as りんご (never katakana, nor kanji), but I don't want to be a Japanese language Internet troll. (Yes, there are many: "Oh, but actually...")
All of the stats are calculated by me analyzing texts from my corpus. If you follow the link that I've pasted and click on "Used in" then you can see where exactly this form of the word is used.
リンゴ is used in: https://jpdb.io/vocabulary/1555480/リンゴ/used-in
林檎 is used in: https://jpdb.io/vocabulary/1555480/林檎/used-in
So you can see that the kanji form is used relatively often in novels (which makes sense, as those often use higher level/more flower-y language).
(I also use modern news articles in my corpus and that's also included in the stats, although this isn't shown on the "used in" pages.)
林檎 for sure is common.
FYI, while this word is most often written in kana it's also often written in kanji.
Source: I run a website with such stats. See "Alt. forms" here: https://jpdb.io/vocabulary/1555480/リンゴ