*Excludes Observations that spanned multiple years

Pre 197015
19700
19710
19720
19730
19740
19750
19761
19770
19780
19790
19803
19816
19821
19832
19840
19850
19862
19870
19880
19890
19903
19912
19922
19930
19940
19952
19961
19971
19980
19991
20000
20010
20020
20030
20040
20050
20060
20076
200837
20090
20100
20110
20120
20131
20140
20150
20160
20170
20180
Total86