  We calculate and analyze the distribution of period ratios observed in
systems of Kepler exoplanet candidates including studies of both adjacent
planet pairs and all planet pairs. These distributions account for both the
geometrical bias against detecting more distant planets and the effects of
incompleteness due to planets missed by the data reduction pipeline. In
addition to some of the known features near first-order mean-motion resonances
(MMR), there is a significant excess of planet pairs with period ratios near
2.2. The statistical significance of this feature is assessed using Monte Carlo
simulation. We also investigate the distribution of period ratios near
first-order MMR and compare different quantities used to measure this
distribution. We find that beyond period ratios of ~2.5, the distribution of
all period ratios follows a power-law with an exponent -1.26 +/- 0.05. We
discuss implications that these results may have on the formation and dynamical
evolution of Kepler-like planetary systems---systems of sub-Neptune/super-Earth
planets with relatively short orbital periods.
