condition mean min max ZT0-3 6781.716268 6781.716268 6781.716268 ZT4-7 6466.9508355 6466.9508355 6466.9508355 ZT8-11 6004.0174525 6004.0174525 6004.0174525 ZT12-15 6072.106409 6072.106409 6072.106409 ZT16-19 6057.8063095 6057.8063095 6057.8063095 ZT20-23 5628.696748 5628.696748 5628.696748