*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19854
19866
198716
198821
198912
19909
199119
199210
19932
19942
19951
19960
19973
199814
199919
200012
20016
20020
20031
20045
20054
20062
20071
20081
20094
20103
20112
20120
20131
20141
20152
20167
20174
20180
Total194