backfire can be caused by choke not shutting off completely, also could have a bad distributor cap, bad spark plugs, bad ignition condensor, bad plug leads, or to much fuel getting to carburetor system Consider getting yourself a service manual as it contains many troubleshooting for your car.
Median age* of the population. Over the past 50 years, the median age of the world's population has increased by a mere three years, from 23.6 in 1950 to 26.4 in 2000. (The median marks the point where half the population is older than that age and half is younger). But over the next 50 years, the median age will jump to 37, according to the latest projections made by the United Nations. By 2050, 17 developed countries are expected to have a median age of 50 or more.
There are just over 40 million Americans age 65 and older, and they make up 13 percent of the population. By 2030, when all the baby boomers will have passed age 65, the over-65 crowd will reach 20 percent of the population. At that time the median age of Americans will increase to 39.6 years, up from 37.2 today and a significant increase from a little under 30 in the 1960s and '70s.