The Dow Jones Apartment REIT subindex is down 8.6% year-to-date, though the stocks have rallied in the past month.

道琼斯公寓类REIT分类指数今年以下跌了8.6%，不过上月出现了反弹。

And the system selects a series of subindex to evaluate the mining system on basis of this seven index systems.

础上，又选取一系列子指标进行综合评价。