CREATE TABLE table_12067 ("Team" TEXT, "Stadium" TEXT, "Capacity" FLOAT, "Lowest" FLOAT, "Highest" FLOAT, "Average" FLOAT)

What's the highest lowest number of capacity that ibrox stadium has when the average is larger than 49,143?
SELECT MAX("Lowest") FROM table_12067 WHERE "Stadium" = 'ibrox stadium' AND "Average" > '49,143'
SELECT MAX("Lowest") FROM "table_12067" WHERE "Average" > '49,143' AND "Stadium" = 'ibrox stadium'