Can someone please explain what's going on here?

According to this website, http://nces.ed.gov/programs/digest/d13/tables/dt13_104.20.asp, only 40% of people between the ages of 25 and 29 have a Bachelor's Degree as of 2013. According to this website, http://nces.ed.gov/programs/digest/d13/tables/dt13_326.10.asp, only 43% of people get a Bachelor's Degree in 4 years after starting college, while only 60% of people get a Bachelor's Degree in 6 years after starting college. This means that of the people who go to college, only 60% of them graduate, while 43% of that 60% graduate in 4 years. 43/60 is about 0.72, so that means, only 72% of the people with Bachelor's Degrees got them in 4 years, by age 21 or 22. Since, according to the first website, only 40% of people have Bachelor's Degrees, and 72% of 40% is about 29%, only 29% percent of people should have their Bachelor's Degrees by 21 or 22. However, almost everyone I know has had a Bachelor's Degree since they were 21 or 22, or is in the process of getting a Bachelor's degree by 21 or 22. And it's not just people I know. I'll look up random strangers on facebook, and they've also had Bachelor's Degrees since they were 21 or 22(or will). I don't understand this.