condition mean min max ZT0-3 10.794151666666666 9.874835000000001 11.602699999999999 ZT4-7 9.518675 9.518675 9.518675 ZT8-11 6.623055 6.623055 6.623055 ZT12-15 8.047482500000001 7.17319 8.921775 ZT16-19 6.67192 6.67192 6.67192 ZT20-23 8.959095000000001 8.959095000000001 8.959095000000001