For a prime $p$ and positive integer $n$, let $N(p^n)$ be the number of isomorphism classes of groups of order $p^n$, and let $T(p^n)$ be the number of isomorphism classes of groups of order $p^n$ which are 2-generated.
What can we say about the ratio $T(p^n)/N(p^n)$? Does it always have a limiting value of 1 as $n\rightarrow\infty$, in particular?