Even bigger increases in the older population are expected as more baby boomers enter the retirement years. In 2030, when all of the baby boomers will be 65 or older, there are expected to be 35 senior citizens for every 100 working-age adults, according to Census Bureau projections. At that time, only 57 percent of the population will be between ages 18 to 64, compared with 63 percent in 2012.