OK, ive just completed my spring/summer combined index, this is based upon the relative values of temps, rainfall and sunshine taken from Oxford and Sutton Bonnington with some adjustments to cater for area averages. this is from 1930 as theres no sunshine records from Oxford before then.
The values are combined from my Spring and Summer indexes, although tbh my Spring one is "mark 1" and needs to be updated which wont be done until next year. (busy on Autumn and September indexes atm)
The top 20 are
2022 - 1424
1976 - 1309
1995 - 1279
1990 - 1274
2011 - 1250
1949 - 1213
2020 - 1205
1933 - 1197
2003 - 1182
1959 - 1154
2018 - 1152
2009 - 1138
1940 - 1131
1975 - 1113
1989 - 1096
1952 - 1091
2015 - 1090
2013 - 1084
1955 - 1049
1934 - 1047
The bottom 20 are
2007 - 795
2004 - 782
1965 - 780
1941 - 777
1951 - 775
1936 - 772
1971 - 771
1998 - 769
1958 - 760
1988 - 752
1985 - 751
1987 - 736
1954 - 731
1968 - 724
1948 - 714
1932 - 662
2012 - 654
1969 - 623
1931 - 605
(1981 - 595 ... might be wrong)
Oh, and 2023 will not make the bottom 20, but be somewhere between there and half way... so bottom half.