*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
19875
19881
19896
19908
19912
199211
19934
19941
19955
19964
19972
19982
199916
200018
200116
20024
20030
20040
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
20180
Total105