condition mean min max ZT0-3 2.380065316 1.7727385119999999 2.98739212 ZT4-7 4.26483274025 3.8370733900000005 4.6925920905 ZT8-11 4.004925248999999 3.786991244 4.222859253999999 ZT12-15 10.91157549225 8.1684618395 13.654689144999999 ZT16-19 12.920806774999999 12.706515934999999 13.135097615 ZT20-23 14.3234769825 13.722547615 14.92440635