How common is O negative in different populations and ethnic groups?

The prevalence of O negative (blood group O and Rh negative) varies by ethnicity. In Caucasian populations roughly 7-9% may be O negative. In African-descent populations it is lower (around 4-5%) and among many Asian populations it is even rarer (<1%). For example in India, O positive is ~32.5% and O negative much smaller (about ~2% according to one dataset). So while globally type O is common, Rh negative (and especially O negative) is much less common and varies significantly by region and ethnicity.