  The orbits of the confirmed exoplanets from all multiple systems known to
date are investigated. Observational data from 1890 objects, of which 1176 are
found in multiplanetary systems, are compiled and analyzed. Mean motion
resonances and near-resonances up to the outer/inner orbital period ratio's
value of 5 and the denominator 4 are tested for all adjacent exoplanet orbits.
Each host star's snow line is calculated using a simple algorithm. The planets
are reclassified into categories as a function of the semimajor axis size
relative to the snow line location and the semimajor axis vs mass distribution.
The fraction of planets in/near resonance is then plotted as a function of both
resonance number and resonance order for all the exoplanet population and,
separately, for each planet type. In the resonance number plot it appears that
the 2/1 and 3/2 resonances and near-resonances are dominant overall and for the
giant planets, but the observed distribution profile changes significantly with
each planet category, with terrestrial planets, neptunes and mini-neptunes
showing the largest variation. Resonances/near resonances around the value 5/3
were dominant for mini neptunes and terrestrial planets. In the order-based
resonance/near-resonance plot, the observed distribution appears to follow an
exponential decay for the general population and its profile appears to be
influenced by the planet type. Approximate methods to estimate resonance/near
resonance distributions are also attempted for the systems with unknown planet
mass or with unknown star and/or planet mass and compared with the distribution
of the planets with all the parameters known. A separate study of the
resonance/near resonance fraction distribution as a function of mass is also
attempted, but the low statistical data at very high planetary masses prevent
the finding of an accurate equation to describe such a dependency.
