In both cases (stochastic/ doubly stochastic) the trace is a number in $[0,n]$ and nothing more can be said about the trace. In other words, for any $a \in [0,n]$ there exists a doubly stochastic matrix with trace $a$.
In both cases (stochastic/ doubly stochastic) the trace is a number in $[0,n]$ and nothing more can be said about the trace. In other words, for any $a \in [0,n]$ there exists a doubly stochastic matrix with trace $a$.