The world now has 15 million millionaires, more than the population of Rwanda. The U.S. leads with nearly 5.5 million millionaires, outnumbering Ireland's entire population. In just 10 years, U.S. millionaires have surged by 62%, holding over a third of the global millionaire total. China and Germany also have impressive numbers, with China having 860,000 millionaires and Germany just over 800,000. Surprisingly, Switzerland's millionaire count of 428,000 is more than Iceland’s population, showi...