SBX eta 15 after  2500 generations: 100 solutions, IGD+ 0.3793 (0.1345 to the closest front), hypervolume 4.7459
SBX eta 2  after  2500 generations: 100 solutions, IGD+ 0.3259 (0.1196 to the closest front), hypervolume 4.9842
SBX eta 2  after 20000 generations: 100 solutions, IGD+ 0.0947 (0.0052 to the closest front), hypervolume 6.2507
the closest front, 0.0695 away: IGD+ 0.0868, hypervolume 6.2985 with 100 points
the whole front: hypervolume 6.7857
