*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19860
19870
19881
19890
19905
19918
19923
19934
19943
19952
19962
19972
19986
19991
20001
20018
20020
20034
20042
20051
20060
20071
20080
20092
20100
20110
20120
20130
20140
20150
20160
20170
Total57