The number and percentage of base tables without keys

WITH base_tables AS (SELECT A.table_schema, A.table_name 
FROM INFORMATION_SCHEMA.tables A
INNER JOIN INFORMATION_SCHEMA.schemata B
ON A.table_schema=B.schema_name
WHERE A.table_type='BASE TABLE'
AND (A.table_schema = 'public'
OR B.schema_owner<>'postgres')),
number_of_base_tables AS (SELECT Count(*) AS number_of_base_tables 
FROM base_tables),
number_of_base_tables_without_keys AS (SELECT Count(*) AS number_of_base_tables_without_keys
FROM INFORMATION_SCHEMA.tables A
INNER JOIN INFORMATION_SCHEMA.schemata B
ON A.table_schema=B.schema_name
WHERE (A.table_schema, A.table_name) NOT IN 
(SELECT table_schema, table_name FROM INFORMATION_SCHEMA.table_constraints
WHERE constraint_type IN ('PRIMARY KEY', 'UNIQUE'))
AND A.table_type='BASE TABLE'
AND (A.table_schema = 'public'
OR B.schema_owner<>'postgres'))
SELECT number_of_base_tables_without_keys, 
(number_of_base_tables-number_of_base_tables_without_keys) AS number_of_base_tables_with_keys,
number_of_base_tables, 
Round(number_of_base_tables_without_keys::decimal*100/number_of_base_tables::decimal,2) AS percentage_of_base_tables_without_keys
FROM number_of_base_tables, number_of_base_tables_without_keys
WHERE EXISTS (SELECT * FROM base_tables);