*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19923
19936
19945
19958
19961
19976
19985
199910
20001
20013
20027
20030
20041
20051
20061
20074
20087
20094
20100
20110
20122
20131
20140
20150
20160
20170
Total76