The CDC[0] links to a report[1] mentioning estimates of anywhere from 60,000 to 2.5 million defensive gun uses per year. I’m not necessarily agreeing with the previous comment, just adding some context.
The authors (one being the notable Alan I. Leshner, MS, PhD) clearly states in the report that those numbers are unreliable:
>> The lack of standardization across databases limits their comparability (NRC, 2005). The absence of clearly defined concepts complicates
data collection and interpretation. For example, definitions of “selfdefense” and “deterrence” are ambiguous (NRC, 2005; Weiner et al.,
2007). There is no standardized method for data collection or collation,
which prevents researchers from harnessing the potential power of data
across multiple datasets
0: https://www.cdc.gov/violenceprevention/firearms/fastfact.htm... 1: http://www.nationalacademies.org/hmd/Reports/2013/Priorities...