condition mean min max ZT0-3 10.895845 10.895845 10.895845 ZT4-7 11.6367665 11.6367665 11.6367665 ZT8-11 12.9796205 12.9796205 12.9796205 ZT12-15 11.153642999999999 11.153642999999999 11.153642999999999 ZT16-19 11.5287225 11.5287225 11.5287225 ZT20-23 12.3912515 12.3912515 12.3912515