in Mäntsälä, 4 of which are open to the public, the rest being private residences. Russian czar Alexander I visited as guest of Ulla Möllersvärd in 1809 in the Mäntsälä manor lying in the town center. The manors emerged in the 17th century as noblemen feoffs. Traditionally the land belonged to the manors. There were many crofts in Mäntsälä and new legislation in 1918 enabled the crofters to claim the land for themselves. In the 1920s the manors were still a sizable land owner in the parish. Mäntsälä is especially known for the Mäntsälä rebellion. About 400 civil guards went shooting to a Social Democratic party rally at Ohkola community hall, interrupting it. In the course of a few days leaders of Lapua Movement and armed civil guards from all over the country arrived to Mäntsälä. The government ordered them arrested, and after a speech by president Svinhufvud on 2 March the situation gradually settled down. The movement disbanded early in spring. World War II brought about 2000 refugees evacuated from Karelia to Mäntsälä. They came mainly from Kirvu and Koivisto. Land was cut from the manors again for the arrivals, reducing manor estate considerably. In 1985 a museum about the Kirvu parish was opened next to the church in the city center. In 1992 an apartment trade fair was held in Mäntsälä. The area is being expanded and since 2006, a train depot lies next to it. A discount chain Tokmanni's head office, logistics center and warehouse, founded in 1989, are in Mäntsälä. Also, Yandex built one of its data centers in Mäntsälä in 2015, with a second data center expected to be built in 2020 by Lehto. Demographics The population of Mäntsälä has stayed quite level for decades, but the building of a motorway up to Järvenpää in the 1970s and the extension to Lahti in 1999 have brought new residents from the metropolitan area. By the middle of the 2000s the new railroad to Lahti has been central in municipality population growth. Many people moved to Mäntsälä because of the railroad, that offered quick commuting to Helsinki. 1749: 1,492 (unconfirmed) 1898: 7,972 (unconfirmed) 1920: 7,666 1930: 7,844 1940: 7,739 1950: 11,072 1960: 10,932 1970: 10,166 1980: 11,267 1990: 14,793 2000: 16,628 2005: 18,226 2007: 18,980 2010: 19 975 2012: 20 478 Urban areas Table of the all statistical urban areas of the municipality. The administrative centre is