*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
197610
19770
19780
19790
19800
19810
19820
19830
19840
19850
198610
19870
19880
198910
19900
199110
199210
199310
199410
19951
199612
199710
199810
19990
200013
200113
200212
200320
200420
200521
20068
20073
20083
20092
20102
20110
20122
20130
20140
20150
20160
20170
Total222