Statistics of on-yomi phonemes/syllables


On-yomi of kanji feel a bit like they all sound alike. For instance, vowels
/o/ and /u/ are over-represented.  
Are there statistics of phoneme counts or syllable counts for on-yomi compared
to kun-yomi? Something like: the top-100 syllables make up 20% of syllables
for kun but 40% for on.

