premise: The population of the United Kingdom is ageing. It has increased from 55.9 million in 1971 to 60.2 million in 2005. That is almost an eight percent increase. However, this change is not spread out evenly across all age groups. In the last thirty or so years, the population aged 65 or over has increased from 13 percent to 16 percent. Within this age group the proportion of the population aged 65 and over and 85 and over increased from 7 percent in the 1970s to 12 percent in 2005. However, the percentage of the population living under the age of 16 has declined from 25 percent in 1971 to 19 percent in 2005. Over the last thirty years, the mean age of the UK population increased from 34.1 years in 1971 to 38.8 in 2005. This ageing is principally due to fertility, although in recent times there has been a decrease in mortality rates, with particular emphasis on older ages.
hypothesis: If an individual was to smoke for at least 10 years, they are more likely to suffer from cancer, heart disease, blockage of vessels and so on