A census is taken simultaneously in all parts of the UK every 10 years. In the 2011 census the total population of the United Kingdom was 63,181,775. It is the fourth-largest in Europe (after Russia, Germany and France), the fifth-largest in the Commonwealth and the 22nd-largest in the world. In mid-2014 and mid-2015 net long-term international migration contributed more to population growth. In mid-2012 and mid-2013 natural change contributed the most to population growth. Between 2001 and 2011 the population increased by an average annual rate of approximately 0.7 per cent. This compares to 0.3 per cent per year in the period 1991 to 2001 and 0.2 per cent in the decade 1981 to 1991. The 2011 census also confirmed that the proportion of the population aged 0–14 has nearly halved (31 per cent in 1911 compared to 18 in 2011) and the proportion of older people aged 65 and over has more than tripled (from 5 per cent to 16 per cent).