condition mean min max ZT0-3 225.580231 225.580231 225.580231 ZT4-7 190.734811 190.734811 190.734811 ZT8-11 221.0795325 221.0795325 221.0795325 ZT12-15 257.57489899999996 257.57489899999996 257.57489899999996 ZT16-19 295.962826 295.962826 295.962826 ZT20-23 353.78308400000003 353.78308400000003 353.78308400000003