CREATE TABLE table_204_639 (id NUMBER, "poll company" CLOB, "source" CLOB, "publication date" CLOB, "psuv" NUMBER, "opposition" NUMBER, "undecided" NUMBER)

what is the number of people in opposition in may 2010 ?
SELECT "opposition" FROM table_204_639 WHERE "publication date" = 'may 2010'
SELECT "opposition" FROM "table_204_639" WHERE "publication date" = 'may 2010'