Mayotte was ceded to France along with the other islands of the Comoros group in 1843. When Comoros voted for independence in the 1970's, Mayotte decided to remain a French "collective". In March 2009, the islands voted overwhelmingly 95.2% to become France's 101st 'departement' effective in 2011. The island is 95% Muslim and many Muslim customs such as polygamy, Islamic-inspired law, and male dominance are commonplace, although all will be reversed in accordance with French law by 2011. A large amount of the island's population is composed of illegal aliens from neighboring Comoros. Despite the island's French ownership, less than half of the population understands French and very few speak French fluently.