*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19811
19820
19832
19840
19853
19867
19873
19881
19893
19903
19912
19923
19932
19947
19952
19963
19970
19983
19991
20000
20012
20020
20035
200410
200510
200610
20072
20084
20096
20106
20118
20121
20135
20143
20154
20161
20170
20180
Total123