*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19863
19873
19881
19899
19902
19912
19922
19931
19946
19952
19961
19976
19981
199913
20000
20015
20020
20030
200410
200513
20060
20072
20080
20090
20100
20112
20120
20130
20140
20150
20162
20170
Total86