Answer: 9.7%
Explanation: I looked at the U.S. Census Bureau, Census of Population, 1850 to 2000, and the American Community Survey, 2010.
I think it does because people tend to shorthand words like "for" to "4" and "you" to "U." sometimes people become overreliant on stuff like that and they use it even in school or in situations where the shouldn't. grammar online is pretty bad in general too.