*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19853
198641
19871
198818
198917
19902
19915
199215
199332
199428
199536
199611
19975
19981
19995
20009
20014
20028
20034
20045
200518
20064
20072
20084
20090
201048
201120
201211
20138
20145
20158
20160
20170
Total379