French President Francois Hollande garnered international attention for his so-called "millionaire tax," which was approved by France's highest court last year. Under it, companies that pay high annual salaries could face a 75% tax rate.

While critics fear the tax will push some wealthy residents to leave the country, the impact is yet to be seen.

Most French billionaires and multimillionaires are based in Paris. The City of Light accounts for nearly three-quarters of the country's wealthiest.