  Let $K$ be a number field. For positive integers $m$ and $n$ such that $m\mid
n$, we let $\mathscr{S}_{m,n}$ be the set of elliptic curves $E/K$ defined over
$K$ such that $E(K)_{\operatorname{tors}}\supseteq \mathscr{T}\cong
\mathbb{Z}/m\mathbb{Z}\times \mathbb{Z}/n\mathbb{Z}$. We prove that if the
genus of the modular curve $X_{1}(m,n)$ is $0$, then `almost all' $E\in
\mathscr{S}_{m,n}$ satisfy that $E(K)_{\operatorname{tors}}= \mathscr{T}$,
i.e., no larger than $\mathscr{T}$. In particular, if $m=n=1$, this result
generalizes Duke's theorem over $\mathbb{Q}$ to arbitrary number fields $K$ for
the trivial torsion subgroup.
