*Excludes Observations that spanned multiple years

Pre 197016
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19870
19880
19890
19900
19910
19920
199310
19940
19953
19960
19970
19980
19990
20000
20010
20020
20030
20040
200515
200621
20075
20085
200922
201046
201118
201213
201324
201421
20156
20161
20170
Total227