*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
19890
19902
19913
199214
19937
19943
19958
19961
19974
19987
19997
20005
200114
20025
200317
200419
200513
200623
20075
200828
200913
20108
20112
20128
201312
20140
20150
20160
20170
Total228