| 年份 | 汤加 |
|---|---|
| 2023 | - |
| 2022 | 0.762514 |
| 2021 | 0.716469 |
| 2020 | 0.298192 |
| 2019 | -0.158486 |
| 2018 | -0.20146 |
| 2017 | -0.208448 |
| 2016 | -0.322299 |
| 2015 | -0.404477 |
| 2014 | -0.362636 |
| 2013 | -0.316383 |
| 2012 | -0.0910786 |
| 2011 | 0.142119 |
| 2010 | 0.15206 |
| 2009 | 0.127909 |
| 2008 | 0.204996 |
| 2007 | 0.36466 |
| 2006 | 0.487881 |
| 2005 | 0.531134 |
| 2004 | 0.560121 |
| 2003 | 0.544491 |
| 2002 | 0.537399 |
| 2001 | 0.551696 |
| 2000 | 0.571307 |
| 1999 | 0.589957 |
| 1998 | 0.642428 |
| 1997 | 0.422391 |
| 1996 | 0.174903 |
| 1995 | 0.205091 |
| 1994 | 0.197701 |
| 1993 | 0.192874 |
| 1992 | 0.210239 |
| 1991 | 0.244747 |
| 1990 | 0.31105 |
| 1989 | 0.408325 |
| 1988 | 0.518732 |
| 1987 | 0.177941 |
| 1986 | -0.270769 |
| 1985 | -0.255496 |
| 1984 | -0.246932 |
| 1983 | -0.233166 |
| 1982 | -0.193234 |
| 1981 | -0.135173 |
| 1980 | -0.0681735 |
| 1979 | 0.0157282 |
| 1978 | 0.124602 |
| 1977 | 0.79983 |
| 1976 | 1.49415 |
| 1975 | 1.54817 |
| 1974 | 1.49081 |
| 1973 | 1.44875 |
| 1972 | 1.50996 |
| 1971 | 1.59104 |
| 1970 | 1.69631 |
| 1969 | 1.82307 |
| 1968 | 2.02676 |
| 1967 | 2.15472 |
| 1966 | 2.16858 |
| 1965 | 2.29843 |
| 1964 | 2.33408 |
| 1963 | 2.35899 |
| 1962 | 2.36857 |
| 1961 | 2.41164 |
| 1960 | - |