Visualizing Canadian Demographics - 1

This graph shows the population of various age brackets in Canada over time. Source data comes from Statistics Canada.

The graph is somewhat cluttered, however we can see some interesting patterns:

In general, the population of each age bracket tends to increase over time.
Every time one age bracket peaks, we see a similar peak in the next age bracket about a decade later (an echo). This behaviour makes sence, since the age brackets are ten years apart. At first, we would expect these echos to be about the same size. However, we notice that each echo is slightly larger than the peak a decade earlier. I believe this growth is due to immigration.
The 0-4 year bracket has remained relatively flat since 1970. This age bracket reflects Canada's relatively low (and stable) birth rate.
The population of senior citizens (those older than 65) has been increasing constantly. This trend may be due to better health care, leading to longer lives.
We see a "baby boom" following World War II.
As of 2006, the 55-64 age bracket is the fastest growing bracket. These people (affectionately known as "baby boomers" are largely the product of the baby boom in the 1950s.