*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19733
19740
19750
19760
19770
19781
19790
19801
19810
19820
19830
19844
19851
19860
19873
19883
19890
19900
19912
19920
19930
19941
19955
19964
19971
19981
19993
20003
20011
20020
20030
20040
20051
20060
20070
20080
20091
20100
201110
201263
201321
20140
201517
201681
20171
20180
20190
20200
Total232