They found that hiring a new number accounted for this movement a little more than a third of the time—and in 81 percent of those cases, transfers took place from higher- to lower-status universities.

网友核查原句，是number 还是member？雇佣新员工，还是新数字？

a little more than a third of the time 指时间，“三分之一的时间略多一点”。作时间状语，修饰 accounted。