The following table shows the number of acres of farmland in $2010$ in each state.
State| Number of acres of farmland (in millions)
- | :-:
Iowa | $31$
Minnesota | $27$
North Dakota | $40$
South Dakota | $44$
Wisconsin | $15$
**Find the median number of acres.**
$\qquad$ [[☃ numeric-input 1]] million acres