condition mean min max ZT0-3 19.963452 19.963452 19.963452 ZT4-7 17.403791 17.403791 17.403791 ZT8-11 14.3918785 14.3918785 14.3918785 ZT12-15 19.2502145 19.2502145 19.2502145 ZT16-19 13.2312385 13.2312385 13.2312385 ZT20-23 14.343172 14.343172 14.343172