pos. time athlete country venue date
pos .
time
athlete
country
venue
date
number
first second first_number second_number
number parsed year month day
number number(number) text text text date
1 12.21 (+0.7) yordanka donkova bulgaria stara zagora 20 august 1988
how many of the athletes came from the united states ?
WRB JJ IN DT NNS VBD IN DT NNP NNPS .
10
select count ( c3 ) from w where c4 = 'united states'