Twenty years. It's harder going back.

( whilst starfleet knows the name of the colony that she's from, the planet, what they don't know is the origins of the colony, who her people really are. there are humans on the planet, not many, a smaller colony, but it helped una provide a reasonable explanation for being human on an illyrian colony )

It's further away, my ship never passes in the right direction. When we dock we're usually nearer Earth.