*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
19881
19890
19900
19910
19920
19930
19940
19951
19960
19970
19980
19991
20000
20010
20020
20030
20040
20050
20060
20071
20080
20090
201012
201124
20120
20132
201472
201549
2016106
20173
20180
Total272