Hi!
Those percentages are bonuses to their production of ships, making research and gaining money from trade routes. Each of these categories is increased by stated percentage. So when their planet is making 10 MPs for a ship, with 170% bonus it will get additional 17 MPs for 27 MP total output.
Since those bonuses are from different categories, they aren't supposed to be summed.
BR, Iztok
The reason I asked was that I had just started a new game when I saw this on my second move and before maybe my fourth move on another game when I noticed these same numbers each time for different Minor Races. In addition, the Minor Races build constructor before any other race on the council.
