rank heat name nationality time notes
rank
heat
name
nationality
time
notes
number
number
number
list length
number number text text time <c,text>
1 1 lacena golding-clarke jamaica 12.74 q, pb
tell me the number of competitors from nigeria .
VB PRP DT NN IN NNS IN NNP .
3
select count ( c3 ) from w where c4 = 'nigeria'