From my personal experience; depends on the rubber type of the tyre. For example on a combined city-highway travel profile (70%-30%) in India, normal MRFs would last about 48 to 50K kms, however softer rubber tyres (more grip, lesser noise ones like Michelin, Yoko etc.) generally last 38-42K kms.
There would be variations off course depending upon roads, tyre age and driving style, but this has been my experience till now.