Question: What percentage of customers from the African region is in the household segment?
SQL: SELECT CAST(SUM(IIF(T2.r_name = 'AFRICA', 1, 0)) AS REAL) * 100 / COUNT(T1.n_nationkey) FROM nation AS T1 INNER JOIN region AS T2 ON T1.n_regionkey = T2.r_regionkey INNER JOIN customer AS T3 ON T1.n_nationkey = T3.c_nationkey WHERE T3.c_mktsegment = 'HOUSEHOLD'