Show all template type codes and the number of documents using each type.
SELECT T1.template_type_code ,  count(*) FROM Templates AS T1 JOIN Documents AS T2 ON T1.template_id  =  T2.template_id GROUP BY T1.template_type_code
SELECT T1.template_type_code ,  count(*) FROM Templates AS T1 JOIN Documents AS T2 ON T1.template_id  =  T2.template_id GROUP BY T1.template_type_code
[{'Template_Type_Code': 'AD', 'count(*)': 3}, {'Template_Type_Code': 'BK', 'count(*)': 5}, {'Template_Type_Code': 'PP', 'count(*)': 4}, {'Template_Type_Code': 'PPT', 'count(*)': 3}]