condition mean min max ZT0-3 716.462826 716.462826 716.462826 ZT4-7 470.9299975 470.9299975 470.9299975 ZT8-11 470.723565 470.723565 470.723565 ZT12-15 487.12928899999997 487.12928899999997 487.12928899999997 ZT16-19 729.7113135 729.7113135 729.7113135 ZT20-23 954.7861665 954.7861665 954.7861665