1968=51,2; 1969=52,2; 1970/71=53,2; 1972/73=56,2; 1974/75=58,2; 1976/77=60,2; 1978/79=63,2; 1980/81=65,2; 1982/83=67,2; 1984/85=69,2; 1986/87=71,2; 1988/89=73,2; 1990/91=76,2; 1992/93=78,2; 1994/95=80,2; 1996/97=82,2; 1998/99=85,2; 2000/01=87,2; 2002/03=89,2 u.a. von:
Report / International Labour Conference. - Geneva : International Labour Office, 1919