Figures are current as of today.

Total # of IDNs registered in .com, .net, .org, .info, .biz:
964,894

By extension:

.com – 699,737 (72.51%)
.net – 197,037 (20.42%)
.org – 18,736 (1.94%)
.info – 25,851 (2.68%)
.biz – 23,533 (2.44%)

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.com & .net figures for language (These are not accurate so allow ±% and a lot of languages are not represented as they got swallowed up in other languages )

.com:
Latin: 164,848 (23.50%)
Greek: 2,712 (0.40%)
Cyrillic: 29,284 (4.20%)
Hebrew: 19,399 (2.70%)
Arabic / Persian etc: 25,795 (3.70%)
India: 3,533 (0.50%)
Thai: 7,022 (1%)
Hiragana / Katakana: 30,464 (4.35%)
Korean: 87,687 (12.50%)
Chinese / Kanji: 322,282 (46%)
Misc.: 6,711 (0.95%)

.net
Latin: 41,857 (21.20%)
Greek: 578 (0.30%)
Cyrillic: 6,624 (3.40%)
Hebrew: 5,665 (2.90%)
Arabic / Persian etc: 11,856 (6%)
India: 732 (0.40%)
Thai: 1,622 (0.80%)
Hiragana / Katakana: 11,287 (5.70%)
Korean: 23,393 (11.90%)
Chinese / Kanji: 91,983 (46.60%)
Misc.: 1,440 (0.73%)

Thanks Mulligan from IDNF.com for the stats