The number of reactors peaked in 2002 at 444, compared with 427 today. The share of electricity they produce is down 12% from its 2006 peak, largely because of post-Fukushima shutdowns in Japan. As a proportion of all electricity generated, nuclear peaked in 1993 at 17% and has now fallen to 10%. The average age of operating plants is increasing, with the number over 40 years old (currently 31 plants) set to grow quite rapidly.