and the period of snow cover are variable; whereas in some years, hardly any snow accumulation occurs, there has recently been a series of unusually snowy winters, peaking in the record year 2010 counting 84 days with a snow cover. Nevertheless, snow accumulation of more than 20 centimetres (8 in) remains exceptional, the record being of snow on 18 February 1979. The warmest months in Bremen are June, July, and August, with average high temperatures of . The coldest are December, January, and February, with average low temperatures of . Typical of its maritime location, autumn tends to remain mild well into October, while spring arrives later than in the southwestern parts of the country. Population Bremen's economy boomed in line with the West German Wirtschaftswunder of the 1950s and 60s. This saw the growth, and permanent settlement, of a large migrant worker population, drawn largely from Turkey and southern Europe. A new wave immigration occurred after the turn of new century, following the entry of Poland, Bulgaria and other former East Bloc countries into the European Union, and after 2015 with the settlement of refugees from Syria and other war-torn regions. By the second decade of the century out of a population (including Bremerhaven) of approximately 680,000, over 115,000 had foreign citizenship, and nearly twice that number, almost a third of the total population, could be classified as having non-German origin/ethnicity. Number of minorities in Bremen by nationality as of 31 December 2021: The recent influx has somewhat moderated the tendency toward an accelerated ageing of the population. As it is, more than half the population of the state of Bremen are over 50, and more than a quarter are over 60. Politics The (municipal assembly) is made up of 68 of the 83 legislators of the state legislature, the Bremische Bürgerschaft who reside in the city of Bremen. The legislature is elected by the citizens of Bremen every four years. Bremen has a reputation as a left-wing city. The port, shipyards and related industries sustained a large and unionised working class. This translated into support for the Social Democrats, considered Bremen's natural governing party. However, in the 1980s mechanization of the port and closure of the city's leading shipbuilder induced an employment crisis and shook the confidence of the party's traditional voter base. The SPD, which had still polled 51% in 1987, lost its effective majority. The once