  Of the seven known double neutron stars (DNS) with precisely measure masses
in the Milky Way that will merge within a Hubble time, all but one has a mass
ratio, $q$, close to unity. Recently, precise measurements of three
post-Keplerian parameters in the DNS J1913$+$1102 constrain this system to have
a significantly non-unity mass ratio of 0.78$\pm$0.03. One may be tempted to
conclude that approximately one out of seven (14\%) DNS mergers detected by
gravitational wave observatories will have mass ratios significantly different
from unity. However J1913$+$1102 has a relatively long merger time of 470 Myr.
We show that when merger times and observational biases are taken into account,
the population of Galactic DNSs imply that $\simeq98\%$ of all merging DNSs
will have $q>$0.9. We then apply two separate fitting formulas informed by 3D
hydrodynamic simulations of DNS mergers to our results on Galactic DNS masses,
finding that either $\simeq$0.004 ${M_{\odot}}$ or $\simeq$0.010 ${M_{\odot}}$
of material will be ejected at merger, depending on which formula is used.
These ejecta masses have implications for both the peak bolometric luminosities
of electromagnetic counterparts (which we find to be $\sim$10$^{41}$ erg
s$^{-1}$) as well as the $r$-process enrichment of the Milky Way.
