*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19854
19867
19870
19882
19893
19905
199111
19923
19934
19943
19952
19962
19972
19986
19993
20002
200115
20021
20034
20042
20051
20060
20071
20080
20092
20100
20110
20120
20130
20140
20150
20162
20170
20180
20190
Total87