  We collect and combine all published data on the vertical atmospheric muon
flux and the muon charge ratio for muon momenta above 10 GeV. At sea level the
world average of the momentum spectra agrees with the flux calculated by E.V.
Bugaev et al. within 15%. The observed shape of the differential flux versus
momentum is slightly flatter than predicted in this calculation. The
experimental accuracy varies from 7% at 10 GeV to 17% at 1 TeV. The ratio of
fluxes of positive to negative muons is found to be constant, at a value of
1.268, with relative uncertainties increasing from approximately 1% at low
momenta to about 6% at 300 GeV.
