http://www.cdc.gov/nchs/data/hestat/asthma03-05/asthma03-05.htm

Asthma prevalence (2005):

7.7% of people in the United States had asthma in 2005.

By sex: 8.8% of females in the United States had asthma in 2005 vs. 6.4% of males.

By race: 6.2% of Hispanics in the United States had asthma in 2005.  4.9% of Asians in the United States had asthma in 2005.  9.2% of American Indians/Alaska natives in the United States had asthma in 2005.  9.5% of Blacks in the United States had asthma in 2005.  7.4% of Whites in the United States had asthma in 2005.

By age: 7.2% of adults (ages 18 and over) in the United States had asthma in 2005.  8.9% of children (ages 0-17) in the United States had asthma in 2005.