*Excludes Observations that spanned multiple years

Pre 197010
19700
19710
19720
19730
19740
19750
19760
19773
19780
19790
19800
19810
19821
19830
19840
19850
19860
19870
19880
19890
19900
19910
19922
19936
19940
19958
199612
199758
19980
199913
20000
20010
20020
20030
20040
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20151
20160
20170
20180
20190
20200
20210
Total114