This is a mesmerizing little animation created by Bill McBride of Calculated Risk. It shows the distribution of the U.S. population by age over time, starting at 1900 and ending with Census Bureau forecasts between now and 2060.

A few things that struck me:

-- Back in the 1900s, only a tiny percentage of Americans lived past the age of 70. Obviously we've made great strides in health care since then.

-- As McBride points out, you can see a big "baby bust" before and during the Great Depression, right before prosperity returns and the Baby Boom strikes. (You can also see the bulge of Baby Boomers ripple through the charts in the latter half of the 20th century.)

-- It's not until the 1990s that you start to see a detectable portion of the country older than 90. And the Census projects that the share of the U.S. population older than 95 will start growing around 2020 or so.

-- Obviously the share of older people in the United States will grow in the next three decades, but it's worth noting that even in 2060, the Census projects that there will be more Americans under the age of 40 than over.

What else stands out to you?