*Excludes Observations that spanned multiple years

Pre 19705
19700
19711
19721
19730
19740
19751
19760
19771
19780
19793
19805
19814
19823
19831
19841
19856
19860
19871
198877
1989141
1990131
1991118
1992199
1993224
1994318
1995251
1996362
1997342
1998380
1999325
2000160
200135
200226
200331
200413
20057
200614
200719
200819
200936
201072
201140
201219
201312
20142
20153
20163
20170
Total3412