*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19875
19886
19890
199012
19911
19923
19931
19947
19954
19961
19974
19982
19991
20006
20014
20022
20033
20040
20051
20064
20070
20080
20093
20100
20110
20120
20130
20140
20150
20160
20170
Total71