SCORES
Everything is multiplied by the difficulty factor. 1-8, Chieftain-Sid.
Population consists of 1 point for every specialist or content citizen in your civ, and 2 points for every happy citizen. This score is multiplied by Difficulty.
Territory is 1 point for every tile within your cultural borders. This score is multiplied by Difficulty.
Future technology I'm not sure on, but it's suppose to be like 50 points per each. This score is multiplied by Difficulty. I think this is broken.
Adding Population + Territory + Technology up gives you your turn score. Adding up every turn score and then dividing by the number of turns played yields the base score. Then the bonus is added.
The bonus is simply by date, the formula is (2050 - Date) * Difficulty. It is awarded for any victory condition.