Tableau de données
| 1981 | 2,71 Md | 1997 | 1,21 Md | 2013 | 3,78 Md |
| 1982 | 2,76 Md | 1998 | 752 M | 2014 | 5,25 Md |
| 1983 | 2,53 Md | 1999 | 1,55 Md | 2015 | 2,16 Md |
| 1984 | 2,92 Md | 2000 | 3 Md | 2016 | 1,47 Md |
| 1985 | 3,16 Md | 2001 | 1,95 Md | 2017 | 1,98 Md |
| 1986 | 1,99 Md | 2002 | 1,76 Md | 2018 | 940 M |
| 1987 | 2,27 Md | 2003 | 2,48 Md | 2019 | 894 M |
| 1988 | 2,25 Md | 2004 | 2,88 Md | 2020 | 514 M |
| 1989 | 2,15 Md | 2005 | 4,03 Md | 2021 | 1,56 Md |
| 1990 | 2,36 Md | 2006 | 5,23 Md | 2022 | 3,26 Md |
| 1991 | 2,47 Md | 2007 | 4,83 Md | 2023 | 1,94 Md |
| 1992 | 1,81 Md | 2008 | 6,94 Md | 2024 | 2,23 Md |
| 1993 | 1,23 Md | 2009 | 3,98 Md | 2025 | 2,19 Md |
| 1994 | 1,59 Md | 2010 | 5,02 Md | 2026 | 2,44 Md |
| 1995 | 1,15 Md | 2011 | 6,43 Md | | |
| 1996 | 1,35 Md | 2012 | 5,68 Md | | |
Tableau de données
| 1985 | 65,4% | 1999 | 26,7% | 2013 | 20,9% |
| 1986 | 60,6% | 2000 | 45,1% | 2014 | 30,7% |
| 1987 | 58,5% | 2001 | 31,4% | 2015 | 16,7% |
| 1988 | 60,9% | 2002 | 27,1% | 2016 | 12,9% |
| 1989 | 52,4% | 2003 | 34,2% | 2017 | 16,4% |
| 1990 | 47,8% | 2004 | 33% | 2018 | 6,9% |
| 1991 | 46,9% | 2005 | 38,2% | 2019 | 6,6% |
| 1992 | 32,7% | 2006 | 41,1% | 2020 | 4,3% |
| 1993 | 21,9% | 2007 | 35,6% | 2021 | 11,1% |
| 1994 | 26,5% | 2008 | 43,5% | 2022 | 19,5% |
| 1995 | 16,1% | 2009 | 33,4% | 2023 | 12,9% |
| 1996 | 18,8% | 2010 | 36,6% | 2024 | 14,5% |
| 1997 | 17,2% | 2011 | 34,7% | 2025 | 13,7% |
| 1998 | 14% | 2012 | 29,8% | 2026 | 14,5% |