Overview of aging
Over the course of the twentieth century, the number of Americans over the age of 65 years increased from 3 million to over 35 million. Concurrently, the population of those over age 85 years has grown from 100,000 to over 4 million and, by the end of the last century, represented the fastest growing segment of society. By 2030, some estimate that the percentage of the overall population over age 65 will reach 70 million, just over 20% of the total population and that 10 million of these people will be over age 85 years (Fig. 1). As the “Baby Boomer” generation reaches the ranks of the oldest-old in 2050, their numbers may swell to over 20 million (Fig. 2). A recent report from the National Institute on Aging entitled 65Þ in the United States: 2005, also points out that this phenomenon is not isolated to the United States. Across the globe, the percentage of the population over 65 years will increase by 25% to 50% over the next 25 years (19).
