Let $B_n$ denote the graph with one vertex and $n$ loops, and $b_{n,k}$ be the number of embeddings of $B_n$ with $k$ regions in an orientable surface. Stahl conjectured that both the mode and the median of the sequence $(b_{n,k}:k\ge 1,2\nmid (n-k))$ are within one unit of the harmonic number $H_{2n}≔{\sum }_{j=1}^{2n}\frac{1}{j}$. In this paper we will confirm the conjecture about the median and disprove the conjecture about the mode. We will show that the mode of the sequence $(b_{n,k}:k\ge 1,2\nmid (n-k))$ belongs to the set $\left\{\lfloor H_{2n}\rfloor -1,\lfloor H_{2n}\rfloor ,\lfloor H_{2n}\rfloor +1\right\}$, and each of these three values can be attained by infinitely many $n$.