condition mean min max ZT0-3 23.564866 23.564866 23.564866 ZT4-7 16.758786999999998 16.758786999999998 16.758786999999998 ZT8-11 15.619084999999998 15.619084999999998 15.619084999999998 ZT12-15 19.9303205 19.9303205 19.9303205 ZT16-19 15.5035135 15.5035135 15.5035135 ZT20-23 16.113684499999998 16.113684499999998 16.113684499999998