*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197253
197311
19740
19750
19760
19770
19780
19791
19803
19810
19820
19831
19840
19850
198615
198727
1988269
198921
199057
199183
199245
199336
19948
199539
199630
199764
19983
19992
20003
20017
200214
200364
200469
200578
200671
200778
200872
200960
2010120
201199
201276
201378
201484
201579
2016103
201778
20180
Total2001