Monotonicity conjecture for successive polyomino counts

Let $P(n)$ denote the number of polyominoes with $n$ cells. Successive-ratio monotonicity conjecture. The sequence

$$\frac{P(n)}{P(n-1)}$$

is increasing. The conjecture is motivated by the available values of $P(n)$ and is stronger than the known fact that the limit of $P(n)/P(n-1)$ exists and equals Klarner's constant. No proof or disproof is supplied in the source.