condition mean min max ZT0-3 38.29105 36.7494 39.8327 ZT4-7 19.83035 19.83035 19.83035 ZT8-11 6.698055 6.698055 6.698055 ZT12-15 0 0 0 ZT16-19 23.67285 23.67285 23.67285 ZT20-23 28.8273 28.8273 28.8273