Period	Persons
1967-01-01	19534242
1972-01-01	20657957
1977-01-01	21756096
1982-01-01	22515389
1987-01-01	22949430
1992-01-01	22794284
1997-01-01	22553978
2002-01-01	21730496
2007-01-01	20882982
2012-01-01	20076727