CREATE TABLE table_63959 ("Name" TEXT, "Nationality" TEXT, "Races won" FLOAT, "Races ridden" FLOAT, "Win average" FLOAT)

What is the average win as a percentage of German racer Rudi Altig, who has ridden in over 79 races?
SELECT AVG("Win average") FROM table_63959 WHERE "Nationality" = 'german' AND "Name" = 'rudi altig' AND "Races ridden" > '79'
SELECT AVG("Win average") FROM "table_63959" WHERE "Name" = 'rudi altig' AND "Nationality" = 'german' AND "Races ridden" > '79'