Show data table
| 1980 | 2.31B | 1996 | 10B | 2012 | 25.1B |
| 1981 | 2.24B | 1997 | 9.54B | 2013 | 24B |
| 1982 | 2.32B | 1998 | 10.3B | 2014 | 23.2B |
| 1983 | 2.32B | 1999 | 10.5B | 2015 | 19.9B |
| 1984 | 2.45B | 2000 | 9.99B | 2016 | 21B |
| 1985 | 2.61B | 2001 | 10.4B | 2017 | 22.9B |
| 1986 | 3.32B | 2002 | 11.4B | 2018 | 25.8B |
| 1987 | 3.98B | 2003 | 14.6B | 2019 | 26.2B |
| 1988 | 4.59B | 2004 | 17.3B | 2020 | 25.5B |
| 1989 | 4.9B | 2005 | 18.7B | 2021 | 30.4B |
| 1990 | 6B | 2006 | 20.4B | 2022 | 31.2B |
| 1991 | 6.2B | 2007 | 24.1B | 2023 | 35.1B |
| 1992 | 7.42B | 2008 | 28B | 2024 | 37.6B |
| 1993 | 7.1B | 2009 | 26B | 2025 | 41B |
| 1994 | 8B | 2010 | 25.8B | 2026 | 45.2B |
| 1995 | 9.94B | 2011 | 27.6B | | |
Show data table
| 1980 | 1.4B | 1996 | 7.98B | 2012 | 19.5B |
| 1981 | 1.61B | 1997 | 8.37B | 2013 | 18B |
| 1982 | 1.88B | 1998 | 9.06B | 2014 | 17.5B |
| 1983 | 2.09B | 1999 | 9.73B | 2015 | 17.9B |
| 1984 | 2.45B | 2000 | 10.6B | 2016 | 19B |
| 1985 | 2.72B | 2001 | 11.4B | 2017 | 20.3B |
| 1986 | 2.94B | 2002 | 11.9B | 2018 | 21.8B |
| 1987 | 3.27B | 2003 | 12.8B | 2019 | 23.4B |
| 1988 | 3.66B | 2004 | 13.9B | 2020 | 22.4B |
| 1989 | 4.14B | 2005 | 14.8B | 2021 | 25.7B |
| 1990 | 4.69B | 2006 | 16B | 2022 | 29.6B |
| 1991 | 4.91B | 2007 | 17.5B | 2023 | 32.4B |
| 1992 | 5.69B | 2008 | 19B | 2024 | 34.8B |
| 1993 | 6.03B | 2009 | 18.7B | 2025 | 36.3B |
| 1994 | 6.72B | 2010 | 19.5B | 2026 | 38.3B |
| 1995 | 7.68B | 2011 | 19.9B | | |
Show data table
| 1980 | 4.89B | 1996 | 11.7B | 2012 | 19.2B |
| 1981 | 5.04B | 1997 | 12B | 2013 | 17.9B |
| 1982 | 5.35B | 1998 | 12.8B | 2014 | 17.6B |
| 1983 | 5.64B | 1999 | 13.4B | 2015 | 18.2B |
| 1984 | 6.13B | 2000 | 14.2B | 2016 | 19.4B |
| 1985 | 6.43B | 2001 | 14.8B | 2017 | 20.5B |
| 1986 | 6.66B | 2002 | 15.3B | 2018 | 21.8B |
| 1987 | 7.13B | 2003 | 15.7B | 2019 | 23.1B |
| 1988 | 7.72B | 2004 | 16.5B | 2020 | 22.4B |
| 1989 | 8.35B | 2005 | 17.3B | 2021 | 24.9B |
| 1990 | 8.97B | 2006 | 18.2B | 2022 | 27B |
| 1991 | 9.03B | 2007 | 19.1B | 2023 | 28B |
| 1992 | 9.88B | 2008 | 19.8B | 2024 | 29.1B |
| 1993 | 9.95B | 2009 | 19.4B | 2025 | 30.2B |
| 1994 | 10.5B | 2010 | 19.8B | 2026 | 31.1B |
| 1995 | 11.6B | 2011 | 19.9B | | |