*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19850
19869
19871
19880
19893
19900
19910
19924
19930
19940
19950
19960
19971
19982
19990
20006
20014
20023
20039
200439
20051
20064
20071
20081
20090
20106
20113
20120
20130
20142
20150
20160
20170
Total100