condition mean min max ZT0-3 342.827414 342.827414 342.827414 ZT4-7 373.37670849999995 373.37670849999995 373.37670849999995 ZT8-11 381.817638 381.817638 381.817638 ZT12-15 356.9914685 356.9914685 356.9914685 ZT16-19 343.3155905 343.3155905 343.3155905 ZT20-23 324.6401 324.6401 324.6401