Some statistics as of the 1st Jan 2300
Number of Explored Systems: 90252
Number of Major Colonies (1 million+):53
Number of Minor Colonies (less than 1 million):51
Number of Outposts (includes mining, research, trade and military):815
Humans have explored over ninety thousand worlds, most only by automated mapping and scouting drones and have settled permanently on only one hundred and four worlds. In 2300 thirty-eight billion humans have classed themselves as living off world but most off world colonies are hard places to live, the vision of a green and lush water filled earth is not repeated very often through this part of the galaxy, most world are too cold, hot, dry or have the wrong atmosphere. Many worlds have been altered by terraforming operations originally pioneered on Mars, although far from bringing a planet to Earth standards the goal of the terraforming operation is to enable colonists to walk the surface of a planet with only the need for some warm clothes and no breathing aids.
Planets are divided into three categories-
Humans are able to breath with minimal aid and operate on the surface with unsealed clothing. Planet can be terraformed with little effort.
Humans can operate on the surface but need artificial aids such as cold suits and breathing apparatus. Living on the se type of planets may require specialised sealed habitats. Planet can be terraformed at great expense.
There is no atmosphere or the one that is there is poisonous, corrosive or otherwise not fit for consumption. Humans cannot live on these planets without extensive investment in life support.