Millennials have some of the worst credit ratings, a new Experian report finds. FICO scores averaged 665 in the fourth quarter for people aged 23 to 38, the data show, compared with a national average of 701. Millennials tied for lowest average score with Generation Z, which includes people between the ages of 18 and 22 and is the youngest group eligible for a credit card. Consumers in their 70s and older had the highest average score, 756, while Baby Boomers ranked next best with an average score of 732. The report also noted that Millennials are financially worse off than they were the year before. They have average total debt of $80,666, up 11 percent from 2017; an average of $34,770 in student loan debt, up 8 percent; and an average credit card balance of $5,231, up 7 percent.