condition mean min max ZT0-3 7.187609166666666 6.695705 7.679513333333333 ZT4-7 13.4176 13.4176 13.4176 ZT8-11 10.936399999999999 10.936399999999999 10.936399999999999 ZT12-15 19.33963125 12.4539625 26.2253 ZT16-19 13.061554999999998 9.53541 16.587699999999998 ZT20-23 0 0 0