After the last ice age began, the number of animal species in Australia changed rapidly. The relationship between the elapsed time, $t$, in years, since the ice age began, and the total number of animal species, $S(t)$, is modeled by the following function: ###$S(t)=4{,}200{,}000\cdot \left(0.72\right)\^{\Large t}$ **Complete the following sentence about the yearly percent change of the number of animal species.** Every year, [[☃ numeric-input 2]]$\%$ of species are [[☃ dropdown 3]] the total number of animal species.