求翻译：截止到2010年11月底，机构投资者持股市值占全部A股流通市值的70%。机构投资者的快速发展，对强化上市公司外部治理机制，发挥着日益突出的积极作用。是什么意思？

As of the end of November 2010, the market value of shares of institutional investors accounted for 70% of a share market capitalization. The rapid development of institutional investors, to strengthen the external governance mechanisms of listed companies are playing an increasingly prominent and p