Research and biology will be the most important factors that determine how long people will be expected to live. With all the research and technology starting to prevail people in the future will live longer and healthier lives. There are many centenari-ans in the world now, that number will continue to rise rapidly in the next 20 years. The longest-lived human on record was 122 years 5 months and 14 days (Fischer 58). This number will easily be surpassed in the future. The average life expectancy in the United States has grown so much in the last 100 years it shows only a promising future. The overall goal is to live a long and healthy life, not just to extend the span. The average life expectancy in the United States has grown from 47 in 1900 to 76 in 1999. In the next century, biology should help more and more people reach the age of 100 (Weiner 74). Currently there are about 61,000 people over the age of 100, by the year 2020, it is predicted that there will be over 214,000 (56). The male sex does not seem to be living as long nor as healthy, 79 percent of the people over 100 are women (58). Although centenarians are rare, they are the fastest growing seg-ment of the United Population. The baby boomers will be one of the first generations to experience the great increase in the life expectancy rate. The Census Bureau projects that one in nine baby boomers will survive into their late 90's, and one in 26 will reach 100. "In 1900, the odds of living that long were one in 500," stated Lynn Adler, founder of National Centenarian Awareness Projections (Cowley 59). Extending the average life expectancy age would be great, but living a healthy life while doing that would be even better. Americans are living longer and healthier. The disability rate among people older than 65 is steadily decreasing. Less and less of them are suffering from hypertension, arteriosclerosis, and dementia (59). In a stud...