condition mean min max ZT0-3 4.701617499999999 3.34793 6.055305 ZT4-7 2.657945 2.657945 2.657945 ZT8-11 3.8467000000000002 3.8467000000000002 3.8467000000000002 ZT12-15 0 0 0 ZT16-19 5.663435 5.663435 5.663435 ZT20-23 6.27669 6.27669 6.27669