*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19870
19883
19891
19900
19910
19923
19932
199412
19958
199614
199713
19981
19998
20003
20010
20021
20036
20044
200523
20060
20070
20084
20094
201017
201130
201217
201315
20148
201517
201619
201720
20180
Total255