*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19757
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19922
19930
19940
19950
19961
19970
19983
19996
20006
20010
20021
20031
20040
20050
20060
20070
20081
20090
20100
20116
20120
20134
20140
20150
20160
20170
Total38