condition mean min max ZT0-3 18.62455 18.62455 18.62455 ZT4-7 33.78725 33.78725 33.78725 ZT8-11 18.9908 18.9908 18.9908 ZT12-15 13.95315 13.95315 13.95315 ZT16-19 9.21335 9.21335 9.21335 ZT20-23 11.16465 11.16465 11.16465