Please clarify. I have read that according to NASA the universe's expansion rate is 74.3 km/s +/- 2.1 at Mega parsec. At a distance of one Mega parsec, space is moving 74 km/s away from us. At 2 Mega parsec it is moving away at 148 km/s. Do I understand this correctly? But this is velocity, it is not acceleration. How fast was it moving away a billion years ago? The velocity must have been less that 74 km/s at 1 Mega parsec if the universe is accelerating. Are we able to measure past values with the red shift?