*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19729
19735
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19858
19863
198728
198819
198910
19908
199113
19928
19938
19945
19958
19961
19976
19985
199912
200013
20014
20027
20030
20042
20051
20061
20074
20087
20095
20100
20112
20123
20131
20141
20150
20160
20172
20187
20190
Total216