condition mean min max ZT0-3 8.01309 8.01309 8.01309 ZT4-7 6.21368 6.21368 6.21368 ZT8-11 7.27329 7.27329 7.27329 ZT12-15 7.803190000000001 7.803190000000001 7.803190000000001 ZT16-19 10.771799999999999 10.771799999999999 10.771799999999999 ZT20-23 8.01859 8.01859 8.01859