What is the rate of expansion of the universe?
The most accurate measurement I know of is 71 ± 4 (km/s)/Mpc,
which was derived from data collected by the WMAP satellite. The
exact value isn't actually known currently, as far as I know. The
rate of expansion seems to be increasing. It seems as though the
further apart objects are, the greater the rate of expansion
between them. At closer distances, gravity is stronger.