*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19761
19770
19780
19791
19800
19810
19820
19834
19841
19850
19867
19875
19886
19890
19900
19911
19920
199312
19943
19952
19960
19970
19980
19990
20000
20011
20022
20030
20040
200513
20060
20070
200811
20090
20100
20110
20120
20131
20141
20150
20160
20170
Total72