What fraction of Japanese words contain digraphs?


I'm curious as to what the percentage of native Japanese words that contain
digraphs, or to put it another way, the average number of digraphs (or
individual kana) in a Japanese word would be. I'm a big math nerd, so as I'm
learning Japanese this popped into my head.




From a 68,000 word dictionary, I counted 22,000 words whose readings include
one, or more, of 「っ, ゃ, ゅ, ょ」. Unfortunately, I triple-counted unusual words
like 出張(しゅっちょう). 「ょ」was in 11,000 of the words while「ゃ」was in just 2,200. I
ignored all katakana.




From a 68,000 word dictionary, I counted 22,000 words whose readings include
one, or more, of 「っ, ゃ, ゅ, ょ」. Unfortunately, I triple-counted unusual words
like 出張(しゅっちょう). 「ょ」was in 11,000 of the words while「ゃ」was in just 2,200. I
ignored all katakana.

