*Excludes Observations that spanned multiple years

Pre 19706
19702
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19823
19830
19840
19850
19860
19871
19883
19890
19900
19910
19920
19935
19942
19955
19960
19971
19982
19994
20005
20011
20020
20030
20040
20054
20060
20072
20080
20093
20100
20112
20120
20131
20140
20150
20160
20170
Total52