*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
19873
19881
19899
19903
19912
19922
19931
19946
19952
19961
19976
19981
199914
20000
20015
20020
20032
200411
200516
20062
20075
20082
20091
20101
20114
20125
20135
20142
20155
20164
20174
20180
Total128