Show data table
| 1970 | 0.3417 Mt | 1989 | 0.313 Mt | 2008 | 0.4631 Mt |
| 1971 | 0.3399 Mt | 1990 | 0.3292 Mt | 2009 | 0.4809 Mt |
| 1972 | 0.3217 Mt | 1991 | 0.3782 Mt | 2010 | 0.5168 Mt |
| 1973 | 0.3246 Mt | 1992 | 0.4911 Mt | 2011 | 0.6166 Mt |
| 1974 | 0.3172 Mt | 1993 | 0.6836 Mt | 2012 | 0.6343 Mt |
| 1975 | 0.3017 Mt | 1994 | 0.7708 Mt | 2013 | 0.5936 Mt |
| 1976 | 0.294 Mt | 1995 | 0.834 Mt | 2014 | 0.5956 Mt |
| 1977 | 0.249 Mt | 1996 | 0.9172 Mt | 2015 | 0.5776 Mt |
| 1978 | 0.2587 Mt | 1997 | 0.8588 Mt | 2016 | 0.5972 Mt |
| 1979 | 0.2868 Mt | 1998 | 0.6394 Mt | 2017 | 0.5861 Mt |
| 1980 | 0.3011 Mt | 1999 | 0.6793 Mt | 2018 | 0.6551 Mt |
| 1981 | 0.3395 Mt | 2000 | 0.6703 Mt | 2019 | 0.6736 Mt |
| 1982 | 0.3176 Mt | 2001 | 0.7353 Mt | 2020 | 0.6715 Mt |
| 1983 | 0.3225 Mt | 2002 | 0.7256 Mt | 2021 | 0.7119 Mt |
| 1984 | 0.3238 Mt | 2003 | 0.7004 Mt | 2022 | 0.7499 Mt |
| 1985 | 0.3332 Mt | 2004 | 0.7174 Mt | 2023 | 0.7642 Mt |
| 1986 | 0.2914 Mt | 2005 | 0.6042 Mt | 2024 | 0.778 Mt |
| 1987 | 0.2966 Mt | 2006 | 0.5434 Mt | | |
| 1988 | 0.3056 Mt | 2007 | 0.5301 Mt | | |
Show data table
| 1970 | 0.27 t | 1989 | 0.16 t | 2008 | 0.16 t |
| 1971 | 0.27 t | 1990 | 0.16 t | 2009 | 0.17 t |
| 1972 | 0.25 t | 1991 | 0.2 t | 2010 | 0.18 t |
| 1973 | 0.24 t | 1992 | 0.27 t | 2011 | 0.21 t |
| 1974 | 0.23 t | 1993 | 0.37 t | 2012 | 0.21 t |
| 1975 | 0.21 t | 1994 | 0.4 t | 2013 | 0.19 t |
| 1976 | 0.2 t | 1995 | 0.41 t | 2014 | 0.19 t |
| 1977 | 0.17 t | 1996 | 0.43 t | 2015 | 0.19 t |
| 1978 | 0.17 t | 1997 | 0.4 t | 2016 | 0.19 t |
| 1979 | 0.18 t | 1998 | 0.29 t | 2017 | 0.19 t |
| 1980 | 0.19 t | 1999 | 0.31 t | 2018 | 0.21 t |
| 1981 | 0.21 t | 2000 | 0.3 t | 2019 | 0.21 t |
| 1982 | 0.19 t | 2001 | 0.32 t | 2020 | 0.2 t |
| 1983 | 0.19 t | 2002 | 0.3 t | 2021 | 0.21 t |
| 1984 | 0.18 t | 2003 | 0.28 t | 2022 | 0.22 t |
| 1985 | 0.18 t | 2004 | 0.28 t | 2023 | 0.22 t |
| 1986 | 0.16 t | 2005 | 0.23 t | 2024 | 0.22 t |
| 1987 | 0.16 t | 2006 | 0.2 t | | |
| 1988 | 0.16 t | 2007 | 0.19 t | | |