condition mean min max ZT0-3 7.3734424999999995 6.569224999999999 8.17766 ZT4-7 8.438085 8.438085 8.438085 ZT8-11 7.54984 7.54984 7.54984 ZT12-15 0 0 0 ZT16-19 6.905565 6.905565 6.905565 ZT20-23 9.938884999999999 9.938884999999999 9.938884999999999