  The Parkes-MIT-NRAO (PMN) radio survey has been used to generate a quasi
all-sky study of Galactic Supernova Remnants (SNRs) at a common frequency of
4.85 GHz. We present flux densities estimated for the sample of 110 Southern
Galactic SNRs (up to Dec = - 65 deg.) observed with the Parkes 64-m radio
telescope and an additional sample of 54 from the Northern PMN (up to Dec = +64
deg.) survey undertaken with the Green Bank 43-m (20 SNRs) and 91-m (34 SNRs)
radio telescopes. Out of this total sample of 164 selected SNRs (representing
71% of the 231 known SNRs in the Green catalogue) we consider 138 to provide
reliable estimates of flux density and surface brightness distribution. This
sub-sample represents those SNRs which fall within carefully chosen selection
criteria which minimises the effects of the known problems in establishing
reliable fluxes from the PMN survey data. Our selection criteria are based on a
judicious restriction of source angular size and telescope beam together with
careful evaluation of fluxes on a case by case basis. This gives confidence in
the newly derived PMN fluxes when the selection criteria are respected. We find
a sharp drop off in the flux densities for Galactic SNRs beyond 4 Jy and then a
fairly flat distribution from 5-9 Jy, a slight decline and a further flat
distribution from 9-20 Jy though the numbers of SNR in each Jy bin are low. We
also re-visit the contentious Sigma-D relation to determine a new power law
index for a sub-sample of shell type SNRs which yields beta= -2.2 +/- 0.6. This
new evaluation of the Sigma-D relation, applied to the restricted sample,
provides new distance estimates and their Galactic scale height distribution.
We find a peak in the SNR distribution between 7-11 kpc with most restricted to
+/- 100 pc Galactic scale height.
