*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19764
19772
19782
19790
19800
19810
19821
19830
19840
19851
19860
19870
19880
19890
19900
19910
19921
19932
19942
199510
199620
19978
19983
19997
20000
20010
20022
20032
20040
20050
20061
20070
20083
20090
20100
20110
20121
20131
20141
20150
20160
20170
20180
Total74