*Excludes Observations that spanned multiple years

Pre 19702
19700
19710
19720
19730
19740
19750
19760
19770
19781
19791
19802
19812
19821
198314
19841
19850
198642
19872
198810
198917
199015
199117
199231
199344
199435
199599
19965
199753
199850
199939
20008
200151
200213
20037
200471
200581
200619
200712
200832
200910
201080
201178
20128
201310
20149
20155
201616
20170
Total993