  We introduce the violation fraction $\upsilon$ as the cumulative fraction of
time that a mesoscopic system spends consuming entropy at a single trajectory
in phase space. We show that the fluctuations of this quantity are described in
terms of a symmetry relation reminiscent of fluctuation theorems, which involve
a function, $\Phi$, which can be interpreted as an entropy associated to the
fluctuations of the violation fraction.
  The function $\Phi$, when evaluated for arbitrary stochastic realizations of
the violation fraction, is odd upon the symmetry transformations which are
relevant for the associated stochastic entropy production. This fact leads to a
detailed fluctuation theorem for the probability density function of $\Phi$.
  We study the steady-state limit of this symmetry in the paradigmatic case of
a colloidal particle dragged by optical tweezers through an aqueous solution.
Finally, we briefly discuss on possible applications of our results for the
estimation of free-energy differences from single molecule experiments.
