Webster Online Rosetta Edition says:
Usage Frequency: "I"
"I" is generally used as a pronoun (personal) -- approximately 97.71% of the time. "I" is used about 904,364 times out of a sample of 100 million words spoken or written in English. Its rank is based on over 700,000 words used in the English language. Some parts-of-speech are not covered due to the samples used by the British National Corpus. (note: percents less than one-hundredth of one percent have been omitted)
Parts of Speech Percent Usage per 100 Million Words Rank in English
Pronoun (personal) 97.71% 883,662 11
Cardinal Number 0.94% 8,500 1,135
Alphabetical Symbol 0.87% 7,832 1,235
Unclassified Items 0.35% 3,132 3,001
Noun (proper) 0.14% 1,234 6,330
Total 100.00% 904,364 N/A
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