condition mean min max ZT0-3 1.805885 1.748545 1.863225 ZT4-7 2.80179 2.80179 2.80179 ZT8-11 4.0153300000000005 4.0153300000000005 4.0153300000000005 ZT12-15 0 0 0 ZT16-19 5.52924 5.52924 5.52924 ZT20-23 3.67082 3.67082 3.67082