Using the latest info from this site, SPP appears to be heading towards its mean PE range of 17.158. A PE between 14.6 and 17.158 is 1 Std below the mean. I am not sure if it will drop further, but I have bought SPP reasonably successfully based upon its PE trading range, buying when it dips below its mean or close to the mean. PE range according to Std Devs is as follows:
17.158 = mean 14.612 - 17.158 = -1 Std dev. 12.065 - 14.612 = -2 to -1 Std dev
Add or subtract about 2.547 up or down for each Std Dev. I am not punting this, but i have been watching, tracking and buying SPP since it listed, so its a point of interest to me.