*Excludes Observations that spanned multiple years

  B
b
t
W
w
 
Pre 19701080020110
1970400206
1971700108
1972700108
1973800109
1974400206
19757003010
19769002011
197712002014
19789001010
197915006021
198016002018
198115000015
198216006022
198312003015
198417005022
198515004019
198621007230
1987170022241
1988190021141
1989220029455
1990171221335
19911516211154
199214131986123
1993211215351390
199419052312591306
199518441215871625
199614121512341266
1997221213406444
1998251211671710
19991711584108
20002712209741024
2001301419657711
200221104310251090
2003201031797849
200421023210391094
2005282245159236
2006252166697791
2007300076713819
20083092105318464
2009220312274221
20103101200328560
20114603264297610
2012462075418541
2013301398333735
2014200210323535
201510138444
2016000189
201700110112
2018100001
Total926315220131387616898