How would you define a normal rate? The Bond Market has been in a substantial uptrend for close to 25 years, which is inversely related to rates. So we have been in a declining rate environment for 25 years ( the lows in price/highs in yield, were made in 82 ). Where would you identify a normal rate, 1/4 of the way, 1/2, 3/4, etc.. It is not as if we have see sawed up and down for 20 years and are at the lows, we have gone straight down for a long period, so finding a normal rate is no easy chore.
I do not have this answer, but I suspect rates will stay low for a very long time, just based on it being such a long term trend. We are close to making a high in rates right now I believe, there are some big picture patterns that are going to enter in to the picture shortly calling for a major low in price ( high in rates ).