*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
19951
19960
19970
19981
199929
20003
20010
20020
20035
20041
20052
20060
20071
20081
20091
201023
20119
20129
201317
201415
201511
201617
201710
20180
Total156