condition mean min max ZT0-3 7.104119 7.104119 7.104119 ZT4-7 8.9649575 8.9649575 8.9649575 ZT8-11 8.407943 8.407943 8.407943 ZT12-15 8.109346 8.109346 8.109346 ZT16-19 8.7819495 8.7819495 8.7819495 ZT20-23 7.9534035 7.9534035 7.9534035