*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19811
19820
19830
19840
19850
19863
19870
19880
19893
19908
19914
19922
19934
19940
19951
19962
19972
19982
19990
20000
20010
20020
20030
20040
20052
20060
20071
20080
20090
20100
20110
20120
20130
20140
20150
20165
20170
Total42