Some Demographic Trends from 1980 to 2009

Now that UCLA's quarter is over, permit me to do some educating.  Here is a set of facts about the age distribution of the U.S population in calendar years 1980, 1990, 2000 and 2009.    All of these facts are measured in millions.

FACT #1  Total population grew from 226.5 in 1980 to 307 in 2009 (so that's a 36% increase in 29 years --- not so big).

FACT #2:   The population ages 5-24 grew from 77 in 1980 to 82 in 2009 (so that's a tiny 6% increase in 29 years)

FACT #3:  The population ages 55+  grew from 47 million in 1980 to 74 million in 2009 (so that's a 57% increase in 29 years)

FACT #4;  The population over the age of 75  grew from 10 million in 1980 to 19 million in 2009 (a 90% increase)

FACT #5;  The median age of the population increased from 30 in 1980 to 36.8 in 2009.

FACT #6;  Conditional that you are over age 85 in the year 2009, the ratio of women to men is over 2 to 1!  How's that for a dating market for Abe Simpson?

What do facts #1-6 mean for the macro economy over the next 20 years?  Can an economy's long term growth ever be accelerated because of aging?   What type of strange endogenous technological change story would one need to dream up to explain how anticipated population aging patterns trigger investments today that help to accelerate long run growth?