*Excludes Observations that spanned multiple years

Pre 197011
19700
19710
19721
19731
19740
19750
19761
19770
19780
19790
19801
19811
19820
19831
19840
19850
19860
19870
19880
19890
19900
19910
19920
19930
19941
19950
19961
19970
19981
19991
20001
20010
20020
20030
20040
20050
20060
20070
20080
20092
20100
20110
20121
20130
20140
20150
20160
20170
Total25