| 年份 | 汤加 |
|---|---|
| 2023 | - |
| 2022 | 0.790139 |
| 2021 | 0.722298 |
| 2020 | 0.28829 |
| 2019 | -0.189433 |
| 2018 | -0.251704 |
| 2017 | -0.276617 |
| 2016 | -0.391826 |
| 2015 | -0.473801 |
| 2014 | -0.433288 |
| 2013 | -0.384919 |
| 2012 | -0.101342 |
| 2011 | 0.212099 |
| 2010 | 0.222816 |
| 2009 | 0.198061 |
| 2008 | 0.27532 |
| 2007 | 0.420998 |
| 2006 | 0.525912 |
| 2005 | 0.566767 |
| 2004 | 0.597769 |
| 2003 | 0.582095 |
| 2002 | 0.573876 |
| 2001 | 0.589858 |
| 2000 | 0.607085 |
| 1999 | 0.628552 |
| 1998 | 0.678217 |
| 1997 | 0.461035 |
| 1996 | 0.217813 |
| 1995 | 0.24636 |
| 1994 | 0.239932 |
| 1993 | 0.233457 |
| 1992 | 0.252182 |
| 1991 | 0.286239 |
| 1990 | 0.35311 |
| 1989 | 0.448253 |
| 1988 | 0.560076 |
| 1987 | 0.322929 |
| 1986 | 0.0236951 |
| 1985 | 0.0340071 |
| 1984 | 0.0422674 |
| 1983 | 0.0515698 |
| 1982 | 0.0877297 |
| 1981 | 0.142596 |
| 1980 | 0.209095 |
| 1979 | 0.28952 |
| 1978 | 0.395681 |
| 1977 | 0.97082 |
| 1976 | 1.53296 |
| 1975 | 1.58508 |
| 1974 | 1.5289 |
| 1973 | 1.48541 |
| 1972 | 1.54762 |
| 1971 | 1.62859 |
| 1970 | 1.73435 |
| 1969 | 1.8608 |
| 1968 | 2.0648 |
| 1967 | 2.39116 |
| 1966 | 2.67733 |
| 1965 | 2.79598 |
| 1964 | 2.82329 |
| 1963 | 2.83526 |
| 1962 | 2.83726 |
| 1961 | 2.86968 |
| 1960 | - |