in 2007, for the first time in the country's history, there were more people over the age of 60 than there were under the age of 16. Peaks and bands within the population represent different periods in which people were born, for example, a large peak of people in particularly for those aged 70–74 born following the Second World War and a wide band for those aged 50–59, born during the 1960s baby boom. Those aged 80 upwards would have been born in the 1930s baby dearth when the birth rate was below replacement level. On the younger band of the population there is a noticeable gap between the ages of 14 to 20, this due to at the beginning of the 21st century a lower number of children being born (and a subsequent lower TFR), however in the years following the birth rate rose during the 2010s and a 'broadening' of the pyramid began for those in the younger years leading to more children in those age cohorts. In relation to the sex ratio of the country, in the higher ages of the population, there are more women than men reflecting the higher life expectancies of women in the population, in the lower ages there are more men than women because there are slightly more boys than girls born each year. In relation to the older age brackets, In 2015, there were estimated to be over half a million people (556,270) aged 90 and over living in the UK, up from 194,670 people in 1985, and there were estimated to be 14,570 centenarians (people aged 100 or over) and 850 people aged 105 or over. The Office of National Statistics has also wrote in their mid-2016 report on population projections that the median age of the British population was 40 years of age, and this will continue to rise as more people in the population age and a below-replacement level fertility level not refilling the population. This will make the number of people aged 85 and over double from 1.6 million in mid-2016 to 3.2 million in mid-2041. The demographic ageing of the population is not evenly spread geographically, as people in rural areas are typically of a higher age than those living in metropolitan areas such as Greater London for example. Urbanisation and population density Population density The United Kingdom is one of the most densely populated countries