Tabella dei dati
| 1981 | 46,4% | 1997 | 35,9% | 2013 | 28% |
| 1982 | 35% | 1998 | 32,4% | 2014 | 31,3% |
| 1983 | 41,2% | 1999 | 38,9% | 2015 | 27,1% |
| 1984 | 41,4% | 2000 | 39,6% | 2016 | 28,1% |
| 1985 | 45,1% | 2001 | 38,1% | 2017 | 26,1% |
| 1986 | 45,3% | 2002 | 35% | 2018 | 30,2% |
| 1987 | 46,9% | 2003 | 24,5% | 2019 | 22,8% |
| 1988 | 46,7% | 2004 | 32,8% | 2020 | 29,1% |
| 1989 | 36,7% | 2005 | 29,5% | 2021 | 30,9% |
| 1990 | 28,6% | 2006 | 33,4% | 2022 | 25,1% |
| 1991 | 30,3% | 2007 | 34% | 2023 | 24,1% |
| 1992 | 31% | 2008 | 33,5% | 2024 | 26,5% |
| 1993 | 39,9% | 2009 | 38,5% | 2025 | 27,8% |
| 1994 | 37,7% | 2010 | 43,5% | 2026 | 32,1% |
| 1995 | 37,7% | 2011 | 33,1% | | |
| 1996 | 40,4% | 2012 | 33% | | |
Tabella dei dati
| 1981 | 575 mln | 1997 | 4,66 mld | 2013 | 30,7 mld |
| 1982 | 498 mln | 1998 | 4,95 mld | 2014 | 37,8 mld |
| 1983 | 676 mln | 1999 | 6,92 mld | 2015 | 36,2 mld |
| 1984 | 790 mln | 2000 | 7,86 mld | 2016 | 42 mld |
| 1985 | 970 mln | 2001 | 8,38 mld | 2017 | 42,7 mld |
| 1986 | 1,12 mld | 2002 | 8,85 mld | 2018 | 52,1 mld |
| 1987 | 1,45 mld | 2003 | 7,05 mld | 2019 | 42 mld |
| 1988 | 1,77 mld | 2004 | 10,4 mld | 2020 | 54,6 mld |
| 1989 | 1,62 mld | 2005 | 10,5 mld | 2021 | 59,7 mld |
| 1990 | 1,47 mld | 2006 | 13,5 mld | 2022 | 54,4 mld |
| 1991 | 1,75 mld | 2007 | 16,1 mld | 2023 | 57,5 mld |
| 1992 | 1,99 mld | 2008 | 18,3 mld | 2024 | 70,2 mld |
| 1993 | 2,88 mld | 2009 | 23,4 mld | 2025 | 81,5 mld |
| 1994 | 3,12 mld | 2010 | 31 mld | 2026 | 105 mld |
| 1995 | 3,65 mld | 2011 | 28,2 mld | | |
| 1996 | 4,49 mld | 2012 | 32,6 mld | | |
Tabella dei dati
| 1981 | 50% | 1997 | 37,8% | 2013 | 32,5% |
| 1982 | 33,9% | 1998 | 31,1% | 2014 | 28,9% |
| 1983 | 42,2% | 1999 | 40,2% | 2015 | 27,5% |
| 1984 | 39,3% | 2000 | 43% | 2016 | 30,5% |
| 1985 | 54,1% | 2001 | 50,3% | 2017 | 30,6% |
| 1986 | 48,7% | 2002 | 39,3% | 2018 | 31,7% |
| 1987 | 47,5% | 2003 | 34,7% | 2019 | 24,2% |
| 1988 | 45,3% | 2004 | 31% | 2020 | 30,9% |
| 1989 | 46,8% | 2005 | 36,4% | 2021 | 36,6% |
| 1990 | 35,8% | 2006 | 33,4% | 2022 | 32,1% |
| 1991 | 30,8% | 2007 | 33,2% | 2023 | 28,9% |
| 1992 | 34,5% | 2008 | 36,1% | 2024 | 28,3% |
| 1993 | 35,2% | 2009 | 39,3% | 2025 | 30,5% |
| 1994 | 37,9% | 2010 | 41,5% | 2026 | 35% |
| 1995 | 38,6% | 2011 | 36,1% | | |
| 1996 | 37,9% | 2012 | 35,1% | | |
Tabella dei dati
| 1981 | 618 mln | 1997 | 4,91 mld | 2013 | 35,6 mld |
| 1982 | 483 mln | 1998 | 4,75 mld | 2014 | 34,9 mld |
| 1983 | 692 mln | 1999 | 7,15 mld | 2015 | 36,9 mld |
| 1984 | 750 mln | 2000 | 8,53 mld | 2016 | 45,5 mld |
| 1985 | 1,17 mld | 2001 | 11,1 mld | 2017 | 50 mld |
| 1986 | 1,21 mld | 2002 | 9,94 mld | 2018 | 54,7 mld |
| 1987 | 1,46 mld | 2003 | 9,99 mld | 2019 | 44,8 mld |
| 1988 | 1,72 mld | 2004 | 9,87 mld | 2020 | 58 mld |
| 1989 | 2,07 mld | 2005 | 13 mld | 2021 | 70,8 mld |
| 1990 | 1,84 mld | 2006 | 13,5 mld | 2022 | 69,4 mld |
| 1991 | 1,78 mld | 2007 | 15,7 mld | 2023 | 68,8 mld |
| 1992 | 2,22 mld | 2008 | 19,7 mld | 2024 | 74,9 mld |
| 1993 | 2,54 mld | 2009 | 23,9 mld | 2025 | 89,4 mld |
| 1994 | 3,13 mld | 2010 | 29,6 mld | 2026 | 114 mld |
| 1995 | 3,74 mld | 2011 | 30,7 mld | | |
| 1996 | 4,21 mld | 2012 | 34,7 mld | | |