From CNA:
According to the survey, 31% of American Catholics attend Mass once a week, 16% once or twice a month, 32% a few times a year, and 9% once a year. Twelve percent attend Mass daily or more than once a week. Frequent Mass attendance was significant among younger generations. Catholics under the age of 40 attend Mass more frequently than older Catholics, with 17% of 18- to 29-year-olds and 22% of 30- to 39-year-olds attending daily or more than once a week.