The chemical element einsteinium-$253$ naturally loses its mass over time. A sample of einsteinium-$253$ had an initial mass of $540$ grams when we measured it. The relationship between the elapsed time $t$, in months, and the mass, $M(t)$, in grams, left in the sample is modeled by the following function: ###$M(t)=540\cdot \left(\dfrac{1}{8}\right)\^{\Large \frac{t}{2.05}}$ **Complete the following sentence about the rate of change in the mass of the sample.** The sample loses $\dfrac{7}{8}$ of its mass every [[☃ numeric-input 4]] months.