condition mean min max ZT0-3 3.724095 3.724095 3.724095 ZT4-7 2.651955 2.651955 2.651955 ZT8-11 1.72654 1.72654 1.72654 ZT12-15 2.750535 2.750535 2.750535 ZT16-19 6.017704999999999 6.017704999999999 6.017704999999999 ZT20-23 4.5986 4.5986 4.5986