U.S. Heritage Tourism Market Size, Share, Growth Analysis By Age Group (51 to 70, 30 and Under, 31 to 50, 71 and Above), By Booking Channel (Direct Booking, Online Travel Agencies (OTAs), Marketplace Booking), By Type (Cultural Heritage, Natural Heritage, Intangible Heritage), By Region and Companies - Industry Segment Outlook, Market Assessment, Competition Scenario, Statistics, Trends and Forecast 2025-2034