关于more than 的用法

Retail sales rose 0.8 of 1 percent in August, intensifying expectations that personal spending in the july-september quarter would more than double the 1.4 percent growth rate in personal spending for the previous quarter

这句话如何翻译？

零售业增加1.8%在八月!~个人花费预期增长在7月到9月的时候,这个是2.8%比之前的三个月（这里的1.4%是不是指4-6比1-3月增加了1.4%）？------请高手解答。

more than 后面的double 是什么词性？more than 后面可以加动词吗？