*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
19902
19911
19920
19931
19940
19950
19960
19970
19981
19996
20001
20012
20022
20035
20044
200536
20060
20071
20080
20092
20102
20111
20120
20130
20140
20152
20161
20170
Total70