condition mean min max ZT0-3 350.598264 350.598264 350.598264 ZT4-7 257.606354 257.606354 257.606354 ZT8-11 269.2933205 269.2933205 269.2933205 ZT12-15 269.5590465 269.5590465 269.5590465 ZT16-19 298.090776 298.090776 298.090776 ZT20-23 294.3494325 294.3494325 294.3494325