*Excludes Observations that spanned multiple years

Pre 19704
19701
19710
197219
19734
19740
19750
19760
19770
19780
19791
19803
19810
19820
198318
198410
19853
198656
198791
1988146
198961
1990154
1991236
1992111
1993136
199450
199553
199639
199730
199820
199921
20003
20016
200219
200319
200434
2005104
200625
200724
200835
200929
201027
201152
201218
201313
201417
201519
201620
201713
201810
Total1754