*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19901
19913
19920
19930
19947
19951
19961
19970
19981
19990
20000
20012
20021
20032
20040
20051
20060
20071
20083
20094
20100
20110
20120
20130
20140
20150
20160
20170
Total28