condition mean min max ZT0-3 220.348738 220.348738 220.348738 ZT4-7 121.785308 121.785308 121.785308 ZT8-11 142.568283 142.568283 142.568283 ZT12-15 184.075226 184.075226 184.075226 ZT16-19 310.3358055 310.3358055 310.3358055 ZT20-23 314.545002 314.545002 314.545002