*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19822
19831
19842
19850
19862
19872
19887
19890
199011
19919
199217
199330
199411
19954
19968
199723
19989
19996
20004
20017
200218
200314
20045
20051
20061
20075
20087
20091
20100
20119
20122
20132
20143
201514
201614
20173
20181
Total256