As of 1 July 2017, the municipality of Oslo had a population of 672,061, while the population of the city's urban area of 3 December 2018 was 1,000,467.[4][13] The metropolitan area had an estimated population of 1.71 million.[14] The population was increasing at record rates during the early 2000s, making it the fastest growing major city in Europe at the time.[15] This growth stems for the most part from international immigration and related high birth rates, but also from intra-national migration. The immigrant population in the city is growing somewhat faster than the Norwegian population,[16] and in the city proper this is now more than 25% of the total if people with immigrant parents are included.[17]