*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197221
19732
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19855
19860
198714
198816
19891
199035
199186
199239
199324
19940
19950
19960
19970
19982
19991
20000
20010
20020
20030
20043
20052
20062
20073
20084
20093
20101
20112
20121
20131
20141
20152
20169
20176
20180
20190
Total286