*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19751
19762
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19870
19880
19890
19900
19910
19920
19935
19943
19950
19961
19975
19982
199913
200020
200114
200213
200335
200450
2005110
200628
2007188
20081
200911
201029
20117
20120
20130
20140
20150
20160
20170
Total539