An Inhabitant is someone who lives within the local area of a particular Millennium Green, as defined by its Trust Deed. The deed should have a map in it, showing the area and refers a few times to the Inhabitants as the people that the Trust are particularly serving in their endevours. A significant example is in the part about the Annual General Meetings, where it states that the Inhabitants should all be welcome to the meeting and given 14 days notice of it, etc.
With this in mind, Greens should consider, for example, which schools and churches they contact and put their posters up at, and perhaps try to ensure that their committees and Trusts specifically include Inhabitants.