Approximately 100 million AK-47 assault rifles had been produced by 2009, and about half of them are counterfeit, manufactured at a rate of about a million per year. Izhmash, the official manufacturer of AK-47 in Russia, did not patent the weapon until 1997, and in 2006 accounted for only 10% of the world's production. This arm became famous due to its reliability in the most extreme climatic conditions, functioning as perfectly in the desert as in the tundra. It is in official use by the militaries of 55 nations, and has been so influential in military struggle that it has been used on national flags. Prominent examples include the flags of Mozambique and Hezbollah, as well as the East Timorese and Zimbabwean coats of arms.