condition mean min max ZT0-3 0.9809271666666667 0.411408 1.303095 ZT4-7 0.814384 0.814384 0.814384 ZT8-11 1.3044 1.3044 1.3044 ZT12-15 3.451505 2.902505 4.000505 ZT16-19 2.774425 2.774425 2.774425 ZT20-23 2.4426200000000002 2.4426200000000002 2.4426200000000002