*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19911
19921
19930
19940
19952
19961
19970
19981
19990
20002
20012
20022
20034
20046
20053
20060
20070
20088
20090
20102
20112
20127
20131
20140
20150
20160
20170
Total46