Question: How many business rates are related to each cmi cross reference? List cross reference id, master customer id and the number of business rates.
SQL: SELECT T2.cmi_cross_ref_id ,  T2.master_customer_id ,  count(*) FROM Business_Rates AS T1 JOIN CMI_Cross_References AS T2 ON T1.cmi_cross_ref_id  =  T2.cmi_cross_ref_id GROUP BY T2.cmi_cross_ref_id