rank nation gold silver bronze total
rank
nation
gold
silver
bronze
total
number
number
number
number
number
number text number number number number
1 soviet union 26 17 15 58
what is the difference between the number of medals the first ranked team had and the number of medals the 21st ranked teams had ?
WP VBD-AUX DT NN IN DT NN IN NNS DT JJ VBD NN VBD-AUX CC DT NN IN NNS DT JJ VBD NNS VBD-AUX .