rank nation gold silver bronze total
rank
nation
gold
silver
bronze
total
number
number
number
number
number
number text number number number number
1 nigeria 13 5 6 24
which african country had more total medal wins then nigeria ?
WDT JJ NN VBD-AUX RBR JJ NN VBZ RB NNP .
South Africa
select c2 from w where c6_number > ( select c6_number from w where c2 = 'nigeria' )