*Excludes Observations that spanned multiple years

Pre 19702
19700
19710
19720
19731
19740
19750
19760
19771
19781
19791
19800
19810
19821
19830
19841
19859
198616
198741
19880
19894
19900
19910
19928
19932
19940
19950
19960
19971
19981
19991
20000
20010
20020
20030
20041
20050
20060
20070
20080
20091
20100
20110
20120
20130
20140
20150
20160
20170
Total93