condition mean min max ZT0-3 854.559214 854.559214 854.559214 ZT4-7 508.8122665 508.8122665 508.8122665 ZT8-11 592.666133 592.666133 592.666133 ZT12-15 623.895671 623.895671 623.895671 ZT16-19 963.8015745 963.8015745 963.8015745 ZT20-23 1072.3648375 1072.3648375 1072.3648375