condition mean min max ZT0-3 282.265015 282.265015 282.265015 ZT4-7 329.7780605 329.7780605 329.7780605 ZT8-11 297.76613399999997 297.76613399999997 297.76613399999997 ZT12-15 284.215484 284.215484 284.215484 ZT16-19 257.21448150000003 257.21448150000003 257.21448150000003 ZT20-23 217.8543505 217.8543505 217.8543505