Global Mattress Market Assessment, By Product Type [Innerspring or coil, Foam, Hybrid, Airbeds, Others], By Comfort [Firm, Medium, Soft], By Technology [Standard Mattress, Smart Mattress], By Size [Single, Double, King, Queen, Others], By End-user [Residential, Commercial], By Price Range [Value Segment, Premium Segment, Luxury Segment], By Distribution Channel [Online, Offline], By Region, Opportunities and Forecast, 2017-2031F