CREATE TABLE table_20581 ("Platform" FLOAT, "Frequency  ( per hour ) " FLOAT, "Destination" CLOB, "Service Pattern" CLOB, "Operator" CLOB, "Line" CLOB)

How many frequency figures are given for next station service pattern?
SELECT COUNT("Frequency (per hour)") FROM table_20581 WHERE "Service Pattern" = 'Next station'
SELECT COUNT("Frequency (per hour)") FROM "table_20581" WHERE "Service Pattern" = 'Next station'