*Excludes Observations that spanned multiple years

Pre 197018
19700
19710
19721
19731
19740
19750
19761
19770
19780
19790
19800
19811
19820
19830
19840
19850
19860
19870
19881
19890
19900
19910
19922
19930
19940
19952
19960
19970
19980
19990
20000
20010
20020
20030
20040
20050
20060
20070
20084
20096
20100
20110
20120
20130
20141
20150
20160
20170
20180
20190
20200
20210
Total38