A 55-year-old man attends his family physician in Toronto for an annual review. He has no past medical history. Over three separate visits, his automated office blood pressure (AOBP) readings are 137/86, 136/84, and 135/85 mm Hg. He is a non-smoker, BMI 27 kg/m², and has no target organ damage. According to current Canadian recommendations, which blood pressure threshold using validated AOBP best defines the diagnosis of hypertension in this patient?