Answer
Not over an extended period of time.
Work Step by Step
Step 1. The leading term of the function is $-0.87x^3$ with a coefficient of $-0.87$ and an odd power. Thus, we can identify its end behaviors as $x\to\infty, y\to-\infty$; that is, the curve falls to the right.
Step 2. This model can be used to predict the number of thefts for a limited number of years if the trend shows a decline of thefts. However, for a long period of time, the value of $f(x)$ will eventually be negative, which will not reflect a realistic situation.