My first 5 million estimate was a guess.
The FBI uniform crime reports has it an about 1.4 million violent crimes last year.
Violent Crime - Crime in the United States 2007
In any case, it is no where near 1 out of 4 chance of being a victim of a violent crime.
Its more like less than 1 out of 100 chances and it has been for at least 20 years of FBI stats:
http://www.fbi.gov/ucr/cius2007/data/table_01.html