condition mean min max ZT0-3 224.187516 224.187516 224.187516 ZT4-7 223.79427099999998 223.79427099999998 223.79427099999998 ZT8-11 245.823424 245.823424 245.823424 ZT12-15 231.4988845 231.4988845 231.4988845 ZT16-19 226.6661245 226.6661245 226.6661245 ZT20-23 259.083729 259.083729 259.083729