prevalence

(PREH-vih-lents)
In medicine, a measure of the total number of people in a specific group who have (or had) a certain disease, condition, or risk factor (such as smoking or obesity) at a specific point in time or during a given period of time. For example, the prevalence of breast cancer may show how many women in the U.S. were diagnosed with breast cancer within the past 10 years, including those who are receiving treatment and those who are considered cured, and are still alive on a certain date.