*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19862
198710
19880
198910
19906
19913
199220
199331
199423
199593
19966
199735
199843
199927
20005
200133
200219
200313
200428
200555
200621
200720
200823
200921
201015
201121
201221
201325
201427
201525
201622
201722
20180
Total725