The life expectancy in the UK is 80.1 but it rises on average (and quite steadily post war) at about 1 year of added life expectancy per 3 years. If you live for 30 years, your life expectancy will go up by 10 years. I'm 20 at the moment, and if I live to the CURRENT life expectancy of 80, it would actually be 100~ because of the increase in technology/medicinal breakthrough.
Also, bear in mind that the general life expectancy is affected negatively, rather than positively by anomalies. There are a lot of people who only live until 30 years before the life expectancy (50) but a tiny amount of people who live 30 years above it (110). If you live a decent life in a non-dangerous occupation, don't smoke, don't drink excessively, exercise regularly, don't kill yourself (!) and don't live in high-deprivation areas (for example, caravan parks where the life expectancy is, in men, around 50).
Realistically my generation (born say 1985-1995) will be working until we're at least 85. I for one am glad about it
Oh, and the 1 year of growth per 3 years is liable to get quicker as significant tech breakthroughs continue, for example nano-tech and the genome map, so 100 for people my age is the conservative estimate. The only thing that could reduce it significantly would be some kind of terrible pandemic or a large world war. Both seem relatively unlikely.