*Excludes Observations that spanned multiple years

Pre 197021
19700
19710
19720
19730
19742
19751
19761
19770
19781
19790
19800
19810
19820
19832
19840
19850
19860
19870
19880
19890
19900
19910
19923
19931
19943
19951
19960
19971
19980
19992
20001
20010
20020
20030
20040
20051
20061
20070
20081
20095
20104
20110
20120
20131
20140
20151
20160
20170
Total54