Show data table
| 1980 | 13B | 1991 | 12.7B | 2002 | 22.8B |
| 1981 | 16.7B | 1992 | 13.3B | 2003 | 21.7B |
| 1982 | 17.4B | 1993 | 13.8B | 2004 | 25.2B |
| 1983 | 18.6B | 1994 | 15.1B | 2005 | 28.9B |
| 1984 | 19.2B | 1995 | 16.6B | 2006 | 33.8B |
| 1985 | 21.2B | 1996 | 17.8B | 2007 | 40.5B |
| 1986 | 25.4B | 1997 | 16.6B | 2008 | 52.6B |
| 1987 | 32.5B | 1998 | 16.1B | 2009 | 53.9B |
| 1988 | 16.5B | 1999 | 16.8B | 2010 | 60B |
| 1989 | 9.85B | 2000 | 19.9B | | |
| 1990 | 12.3B | 2001 | 21B | | |
Show data table
| 1980 | 51.3B | 1991 | 312B | 2002 | 1.12T |
| 1981 | 65.8B | 1992 | 372B | 2003 | 1.07T |
| 1982 | 68.8B | 1993 | 414B | 2004 | 1.27T |
| 1983 | 73.3B | 1994 | 506B | 2005 | 1.51T |
| 1984 | 75.3B | 1995 | 571B | 2006 | 1.73T |
| 1985 | 83.2B | 1996 | 691B | 2007 | 2.02T |
| 1986 | 99.9B | 1997 | 746B | 2008 | 2.45T |
| 1987 | 128B | 1998 | 790B | 2009 | 2.52T |
| 1988 | 186B | 1999 | 819B | 2010 | 2.79T |
| 1989 | 209B | 2000 | 947B | | |
| 1990 | 268B | 2001 | 1.01T | | |
Show data table
| 1980 | 464B | 1991 | 657B | 2002 | 1.04T |
| 1981 | 504B | 1992 | 744B | 2003 | 1.02T |
| 1982 | 517B | 1993 | 799B | 2004 | 1.09T |
| 1983 | 525B | 1994 | 843B | 2005 | 1.16T |
| 1984 | 491B | 1995 | 889B | 2006 | 1.22T |
| 1985 | 527B | 1996 | 915B | 2007 | 1.28T |
| 1986 | 501B | 1997 | 905B | 2008 | 1.34T |
| 1987 | 508B | 1998 | 956B | 2009 | 1.42T |
| 1988 | 572B | 1999 | 926B | 2010 | 1.47T |
| 1989 | 538B | 2000 | 947B | | |
| 1990 | 593B | 2001 | 982B | | |