condition mean min max ZT0-3 13.509175 12.4389 14.579450000000001 ZT4-7 13.623850000000001 13.623850000000001 13.623850000000001 ZT8-11 17.9762 17.9762 17.9762 ZT12-15 0 0 0 ZT16-19 20.9372 20.9372 20.9372 ZT20-23 19.3631 19.3631 19.3631