isles of Scotland. Lerwick, in Shetland, has four hours more daylight at midsummer than London, although this is reversed in midwinter. Annual average sunshine totals vary from as little as 711–1140 hours in the Highlands and the north-west up to 1471–1540 hours on the extreme eastern and south-western coasts. In common with the rest of the British Isles, wind prevails from the south-west, bringing warm, wet and unstable air from the Atlantic. The windiest areas of Scotland are in the north and west, with parts of the Outer Hebrides, Orkney and Shetland experiencing over 30 days with gales per year. Vigorous Atlantic depressions, also known as European windstorms, are a common feature of the autumn and winter in Scotland. Human geography According to the General Register Office for Scotland, the total population of Scotland stood at 5,168,500 in June 2008, an increase of 2.1% since the census of April 2001. Scotland's share of the United Kingdom population has been declining in recent years and stands at just over 8.5% due to differential rates of growth in the home nations. However an increasing birth rate and higher levels of inward migration to Scotland have reversed the decline and contributed to the recent population growth. Compared with the rest of Europe, Scotland has a low population density at 65 people per square kilometre. However Scotland is a highly urbanised country, with 82% of the population living in settlements of 3,000 people or more. As a result, the majority of the population live in the Central Lowlands of Scotland, surrounding the chief cities of Glasgow and Edinburgh. Other concentrations of population include the northeast coast of Scotland – principally surrounding the city of Aberdeen and its environs – and around Inverness. With a population density of 8 people per square kilometre, the Highlands are the most sparsely populated part of the country, and one of the most sparsely populated areas in Europe. In these areas, the population is scattered in villages, small towns and isolated farmsteads or crofts. Nearly 100 of Scotland's islands are inhabited, the most populous being Lewis and Harris with 21,031 people resident in 2011, primarily concentrated around Stornoway, the only burgh of the Outer Hebrides. Other island populations range down to very low levels on certain small isles. Between 1991 and 2001, the total number of people living on Scotland's islands fell by 3%. Conversely, islands such as Tiree,