SELECT AVG(Max_equation_number) AS avg_equation_number, tbl_categories_id FROM ( SELECT *, MAX(equation_number) AS Max_equation_number FROM tbl_risk_bia_relationship where tbl_risk_assessment_id=3106 GROUP BY name,tbl_categories_id ORDER BY tbl_categories_id ASC ) as AssetRegisterCategortyAVG where tbl_risk_assessment_id=3106 GROUP BY tbl_categories_id ;