I don't think it just handful. We literally seen and many Z-8 & Z-18 involved in many exercise in last couple of years in large numbers with even no Mi-17 involved. The production rate I believe is quite high per year with up to 35-40 units. The difficult to get spares and obsolete of Mi-17 means PLA are replacing quite fast at a rate. Given a huge number of Z-8 and Z-18 appear in 70th anniversary celebrration. Estimate a more than hundred has put into service.there is literally hundreds in operation and new Z18 only a hand full
it will be years before they are phased out even if ever