Show data table
| 1970 | 96.17 Mt | 1989 | 57.62 Mt | 2008 | 51.71 Mt |
| 1971 | 88.98 Mt | 1990 | 57.14 Mt | 2009 | 46.92 Mt |
| 1972 | 89.18 Mt | 1991 | 57.64 Mt | 2010 | 52.88 Mt |
| 1973 | 90.27 Mt | 1992 | 60.19 Mt | 2011 | 48.46 Mt |
| 1974 | 83.5 Mt | 1993 | 60.27 Mt | 2012 | 45.73 Mt |
| 1975 | 85.29 Mt | 1994 | 62.94 Mt | 2013 | 43.97 Mt |
| 1976 | 92.39 Mt | 1995 | 62.64 Mt | 2014 | 42.78 Mt |
| 1977 | 88.47 Mt | 1996 | 67.76 Mt | 2015 | 42.9 Mt |
| 1978 | 82.97 Mt | 1997 | 61.8 Mt | 2016 | 42.49 Mt |
| 1979 | 86.11 Mt | 1998 | 63 Mt | 2017 | 41.84 Mt |
| 1980 | 78.63 Mt | 1999 | 61.69 Mt | 2018 | 39.65 Mt |
| 1981 | 71.04 Mt | 2000 | 57.98 Mt | 2019 | 39.5 Mt |
| 1982 | 64.91 Mt | 2001 | 58.06 Mt | 2020 | 38.04 Mt |
| 1983 | 59.08 Mt | 2002 | 59.39 Mt | 2021 | 40.48 Mt |
| 1984 | 58.57 Mt | 2003 | 59.66 Mt | 2022 | 37.75 Mt |
| 1985 | 62.56 Mt | 2004 | 58.07 Mt | 2023 | 36.67 Mt |
| 1986 | 64.21 Mt | 2005 | 54.53 Mt | 2024 | 37.77 Mt |
| 1987 | 62.25 Mt | 2006 | 55.1 Mt | | |
| 1988 | 60.49 Mt | 2007 | 52.84 Mt | | |
Show data table
| 1970 | 11.96 t | 1989 | 6.78 t | 2008 | 5.61 t |
| 1971 | 10.99 t | 1990 | 6.68 t | 2009 | 5.05 t |
| 1972 | 10.98 t | 1991 | 6.69 t | 2010 | 5.64 t |
| 1973 | 11.09 t | 1992 | 6.94 t | 2011 | 5.13 t |
| 1974 | 10.23 t | 1993 | 6.91 t | 2012 | 4.8 t |
| 1975 | 10.41 t | 1994 | 7.17 t | 2013 | 4.58 t |
| 1976 | 11.24 t | 1995 | 7.1 t | 2014 | 4.41 t |
| 1977 | 10.72 t | 1996 | 7.66 t | 2015 | 4.38 t |
| 1978 | 10.03 t | 1997 | 6.99 t | 2016 | 4.28 t |
| 1979 | 10.38 t | 1998 | 7.12 t | 2017 | 4.16 t |
| 1980 | 9.46 t | 1999 | 6.96 t | 2018 | 3.9 t |
| 1981 | 8.54 t | 2000 | 6.54 t | 2019 | 3.84 t |
| 1982 | 7.8 t | 2001 | 6.53 t | 2020 | 3.67 t |
| 1983 | 7.09 t | 2002 | 6.65 t | 2021 | 3.89 t |
| 1984 | 7.03 t | 2003 | 6.66 t | 2022 | 3.6 t |
| 1985 | 7.49 t | 2004 | 6.46 t | 2023 | 3.48 t |
| 1986 | 7.67 t | 2005 | 6.04 t | 2024 | 3.57 t |
| 1987 | 7.41 t | 2006 | 6.07 t | | |
| 1988 | 7.17 t | 2007 | 5.78 t | | |