condition mean min max ZT0-3 14.649647 14.649647 14.649647 ZT4-7 18.146641000000002 18.146641000000002 18.146641000000002 ZT8-11 12.8203325 12.8203325 12.8203325 ZT12-15 14.719209 14.719209 14.719209 ZT16-19 9.9915795 9.9915795 9.9915795 ZT20-23 10.2493155 10.2493155 10.2493155