46RH overdrive ratio.

Just checking figures for 46RH overdrive. 2400 RPM steady level driving. Switch in overdrive - 1850 RPM. This comes out at about 0.77:1 but the overdrive ratio is given as 0.69:1. Switch in lockup and RPM drops to 1650. 2400 to 1650 is a ratio of 0.68:1.

Does the stated ratio include the change due to lockup or is this transmission slipping? What is the ratio due purely to the sun and planet gears in the overdrive?