*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
19850
19860
19870
19881
19890
19900
19910
19921
19934
19940
19954
19968
19971
19980
19990
20001
20010
20020
20030
20040
20050
20060
20070
20081
20090
20101
20110
20120
20130
20140
20151
20162
20170
20180
20190
20200
20211
20221
20230
20240
Total28