condition mean min max ZT0-3 27.31035 27.31035 27.31035 ZT4-7 33.13435 33.13435 33.13435 ZT8-11 52.46925 52.46925 52.46925 ZT12-15 33.01315 33.01315 33.01315 ZT16-19 22.84055 22.84055 22.84055 ZT20-23 19.0546 19.0546 19.0546