CREATE TABLE table_20264 ("Platform" FLOAT, "Frequency  ( per hour ) " FLOAT, "Destination" CLOB, "Service Pattern" CLOB, "Operator" CLOB, "Line" CLOB)

When London Bridge is the destination, what is the frequency?
SELECT "Frequency (per hour)" FROM table_20264 WHERE "Destination" = 'London Bridge'
SELECT "Frequency (per hour)" FROM "table_20264" WHERE "Destination" = 'London Bridge'