*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19920
19930
19940
19950
19960
19970
19980
19990
20000
20011
20020
20033
20049
20053
200611
20075
200819
200938
201031
201126
201242
201329
201421
201523
201613
20171
Total275