  We study the likelihood of energy condition violations in the history of the
Universe. Our method is based on a set of functions that characterize energy
condition violation. FLRW cosmological models are built around these
"indication functions". By computing the Fisher matrix of model parameters
using type Ia supernova and Hubble parameter data, we extract the principal
modes of these functions' redshift evolution. These modes allow us to obtain
general reconstructions of energy condition violation history independent of
the dark energy model. We find that the data suggest a history of strong energy
condition violation, but the null and dominant energy conditions are likely to
be fulfilled. Implications for dark energy models are discussed.
