condition mean min max ZT0-3 32.91661 32.91661 32.91661 ZT4-7 31.4319735 31.4319735 31.4319735 ZT8-11 54.2368245 54.2368245 54.2368245 ZT12-15 47.104513 47.104513 47.104513 ZT16-19 65.330894 65.330894 65.330894 ZT20-23 70.2521475 70.2521475 70.2521475