*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
1972195
197376
19740
19750
19760
19771
19782
19790
19800
19810
19820
19834
198445
198537
198684
1987133
1988249
1989109
1990165
1991169
1992117
199396
199411
199521
19968
199723
199854
1999142
2000140
2001100
200224
200320
200434
200517
200615
200714
20088
200914
20107
201115
20129
201316
201417
201512
201634
201716
20180
20190
Total2253