*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
19894
19905
199116
199214
199338
199416
199557
199614
199738
199821
19999
200027
20015
200210
20031
200429
200519
20061
20070
20080
20090
20100
20110
20120
20131
20141
20150
20160
20170
Total326