*Excludes Observations that spanned multiple years

Pre 19706
19700
19710
19720
19730
19740
19750
19761
19770
19781
19791
19800
19810
19820
19830
19840
19851
19862
19870
19881
19890
19901
19913
19920
19930
19942
19954
19961
19974
19989
19993
20003
20012
20020
20032
20040
20050
20061
20070
20080
20091
20100
20110
20121
20130
20140
20150
20160
20170
20180
Total50