condition mean min max ZT0-3 474.770518 474.770518 474.770518 ZT4-7 456.893072 456.893072 456.893072 ZT8-11 581.6411685 581.6411685 581.6411685 ZT12-15 608.9013125 608.9013125 608.9013125 ZT16-19 988.1910545000001 988.1910545000001 988.1910545000001 ZT20-23 1010.9137805 1010.9137805 1010.9137805