condition mean min max ZT0-3 23.524428 23.524428 23.524428 ZT4-7 58.750588500000006 58.750588500000006 58.750588500000006 ZT8-11 79.073492 79.073492 79.073492 ZT12-15 56.392552 56.392552 56.392552 ZT16-19 48.314192500000004 48.314192500000004 48.314192500000004 ZT20-23 44.158459 44.158459 44.158459