condition mean min max ZT0-3 4.2819525 3.7166449999999998 4.84726 ZT4-7 3.911175 3.911175 3.911175 ZT8-11 4.986319999999999 4.986319999999999 4.986319999999999 ZT12-15 0 0 0 ZT16-19 5.430625 5.430625 5.430625 ZT20-23 4.367975 4.367975 4.367975