Period	Persons
1967-01-01	18228
1972-01-01	19394
1977-01-01	20311
1982-01-01	21989
1987-01-01	23304
1992-01-01	24766
1997-01-01	26114
2002-01-01	28064
2007-01-01	30377
2012-01-01	31247