*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19867
19876
19880
19892
19901
19910
19924
19933
19941
199515
19960
19974
19980
19990
20000
20013
20022
20035
20044
20052
20060
20071
20085
20091
20100
20116
20124
20131
20144
20155
201611
20176
20180
Total103