Show data table
| 1956 | 55.6M | 1976 | 945M | 1995 | 958M |
| 1957 | 48.3M | 1977 | 998M | 1996 | 995M |
| 1958 | 81M | 1978 | 1.21B | 1997 | 1.05B |
| 1959 | 83M | 1979 | 1.58B | 1998 | 1.1B |
| 1960 | 90.2M | 1980 | 2.25B | 1999 | 1.13B |
| 1961 | 90.2M | 1981 | 2.44B | 2000 | 897M |
| 1962 | 150M | 1982 | 2.73B | 2001 | 1.02B |
| 1964 | 112M | 1983 | 2.73B | 2002 | 1.1B |
| 1965 | 118M | 1984 | 3.39B | 2003 | 1.44B |
| 1966 | 102M | 1985 | 3.51B | 2004 | 1.39B |
| 1967 | 119M | 1986 | 3.68B | 2005 | 1.45B |
| 1968 | 190M | 1987 | 3.65B | 2006 | 1.44B |
| 1969 | 195M | 1988 | 3.72B | 2007 | 1.6B |
| 1970 | 200M | 1989 | 1.48B | 2008 | 1.73B |
| 1971 | 177M | 1990 | 1.64B | 2009 | 2.18B |
| 1972 | 260M | 1991 | 2.89B | 2010 | 2.35B |
| 1973 | 389M | 1992 | 2.98B | 2011 | 2.49B |
| 1974 | 537M | 1993 | 1.43B | | |
| 1975 | 888M | 1994 | 1.64B | | |
Show data table
| 1960 | 10.5% | 1978 | 14.7% | 1995 | 6.9% |
| 1961 | 9.5% | 1979 | 15.9% | 1996 | 6% |
| 1962 | 13.5% | 1980 | 17.2% | 1997 | 5.9% |
| 1964 | 8.6% | 1981 | 14.5% | 1998 | 5.8% |
| 1965 | 8.9% | 1982 | 15.6% | 1999 | 5.8% |
| 1966 | 7.7% | 1983 | 14.6% | 2000 | 5.5% |
| 1967 | 8.2% | 1984 | 17.7% | 2001 | 5.5% |
| 1968 | 12.2% | 1985 | 16.6% | 2002 | 5.4% |
| 1969 | 10.8% | 1986 | 14.4% | 2003 | 6.2% |
| 1970 | 11.2% | 1987 | 11.2% | 2004 | 5.5% |
| 1971 | 8.4% | 1988 | 7.9% | 2005 | 5% |
| 1972 | 10.8% | 1989 | 8% | 2006 | 4.4% |
| 1973 | 15.1% | 1990 | 6.9% | 2007 | 4.1% |
| 1974 | 12.7% | 1991 | 10.4% | 2008 | 3.6% |
| 1975 | 15.9% | 1992 | 9% | 2009 | 4% |
| 1976 | 14.7% | 1993 | 7.2% | 2010 | 4.1% |
| 1977 | 14.5% | 1994 | 7.4% | | |