Question: Among the restaurants located on the street number ranges from 1000 to 2000, what is the percentage of Afghani restaurants are there?
SQL: SELECT CAST(SUM(IIF(T2.food_type = 'afghani', 1, 0)) AS REAL) * 100 / COUNT(T1.id_restaurant) FROM location AS T1 INNER JOIN generalinfo AS T2 ON T1.id_restaurant = T2.id_restaurant WHERE 1000 <= T1.street_num <= 2000