Senslope as a percentage


I found a way to express the nonparametric senslope (which is a median slope joining all pairs of observations) by dividing the senslope by the same data mean value. I have done this for all observations (For example: number of injuries observed per quarter over 6 years).

My question now is: Is it wrong if I use the same percentage senslope calculation on percent data? What I mean by this is, if I want to know the percentage slope of "Compliance Rate" data (which is already in a percentage) and I find the senslope and divide that by the mean to get the percentage slope. Is this acceptable?

Thanks so much for your help in advance! It is much appreciated.