*Excludes Observations that spanned multiple years

Pre 19706
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19844
19850
19860
19872
19881
19890
19900
19911
19921
19934
19945
19956
19961
199723
199831
19990
20000
20010
20020
20030
20040
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total85