Back above a billion dollars. That’s where Nevada’s gaming revenue landed in May, totaling 1.04 billion, up 5.3% from a year ago. The state says its the best gaming performance for the start of a year since 2008. Clark County accounted for 86.6 percent of the state’s monthly win total, with $904.6 million. Only downtown Las Vegas and the Boulder strip had gaming revenue declines in May compared to a year ago.