The British decision to leave the European Union, China’s economic slowdown, a strong dollar and other global factors spell trouble for states that depend on international tourists for tax revenue. In Florida, where 23 percent of sales tax revenue comes from tourism, officials are worried that the weakness of the British pound, one effect of the “Brexit” vote, will keep British tourists away and hurt local businesses and tax receipts. Because international travelers typically book their trips 4-6 months in advance, Florida might not feel the effects of the Brexit vote for several more months. Las Vegas has long depended on international visitors, who stay longer and spend more than U.S. tourists. Analysts say slower growth in the number of Chinese visitors, which started two years ago, is showing up in less wagering at high-stakes baccarat tables, a favorite game of Asian tourists.