*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19863
19870
19880
19894
19901
19919
19926
199313
19947
199556
19966
199737
199821
199919
200014
200116
200215
20030
200418
20056
20060
200710
20088
20096
20103
20110
20120
20131
20141
20150
201611
20170
Total291