there's tons of them...
but not on math& stat section...
actually... some people I know who end up in top 50 math PHD program (with full aid) are really SMART and hardworking. Most of them are graduates of USTC.
so I would recommend applicants who want full aid and are not from PKU, THU, USTC, FDU,etc focus on top 50-100 or school after that.
but applying for master program is a different case. and so is applying without need of FA