*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19831
19840
19850
19860
19870
19880
19890
19900
19910
19922
19930
19940
19950
19961
19970
19983
19990
20000
20011
20021
20030
20040
20050
20060
20070
20083
20090
20100
20110
20120
20130
20140
20150
20160
20171
20181
20190
20200
20211
20221
20231
20240
Total18