At the Chinese Academy of Sciences, new members are elected biennially. Before 2014 only a maximum of 60 members could be inducted each time, but this restriction has since been removed by new bylaws. The candidates are nominated by current members or academic groups, although foreign members and senior members cannot nominate new candidates. Self nomination is also not allowed.Available candidates are approved by presidiums of academic divisions. Elections are held by secret ballots, and about 20% of the candidates are elected.