CREATE TABLE table_4144 ("By-election" FLOAT, "Electorate" TEXT, "Date" TEXT, "Incumbent" TEXT, "Reason" TEXT, "Winner" TEXT)

When waikaia is the electorate what is the highest by-election?
SELECT MAX("By-election") FROM table_4144 WHERE "Electorate" = 'Waikaia'
SELECT MAX("By-election") FROM "table_4144" WHERE "Electorate" = 'Waikaia'