I am in the predicament where my grade gradually declined over my final two years at school. This was primarily due to a couple classes where I believe I truly got dicked over which, in turn, led to a less than 100% effort in many other classes. My motivation to do well was pretty much destroyed in these other classes. These excuses are not what the adcoms probably want to hear. So should I just let it be or attempt a tactful approach at addressing the downward trend? Any suggestions? I would prefer to put in an addendum because I have a PS which is turning out to be, in my opinion, a quality essay. Any input would be appreciated.