year conservative
councillors labour
councillors independent
councillors liberal
councillors
year
conservative councillors
labor councillors
independent councillors
liberal councillors
number
number
number
number
number
number number number number number
1947 3 2 18 1
how many years had at least 15 or more independent councillors ?
WRB JJ NNS VBD-AUX IN JJS CD CC JJR JJ NNS .
11
select count ( c1 ) from w where c4_number >= 15