Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_63959 ( "Name" text, "Nationality" text, "Races won" real, "Races ridden" real, "Win average" real )

### Question ###
What is the average win as a percentage of German racer Rudi Altig, who has ridden in over 79 races?

### Accurate SQL ###

SELECT AVG("Win average") FROM table_63959 WHERE "Nationality" = 'german' AND "Name" = 'rudi altig' AND "Races ridden" > '79'