In the 1960s, the population growth of Helsinki began to decrease, mainly due to a lack of housing. Some residents began to move to the neighbouring cities of Espoo and Vantaa, resulting in increased population growth in both municipalities. Espoo's population increased ninefold in sixty years, from 22,874 people in 1950 to 244,353 in 2009. Vantaa saw an even more dramatic change in the same time span: from 14,976 in 1950 to 197,663 in 2009, a thirteenfold increase. These population changes prompted the municipalities of Greater Helsinki into more intense cooperation in areas such as public transportation – resulting in the foundation of HSL – and waste management. The increasing scarcity of housing and the higher costs of living in the capital region have pushed many daily commuters to find housing in formerly rural areas, and even further, to cities such as Lohja, Hämeenlinna, Lahti, and Porvoo.