condition mean min max ZT0-3 9.101663 9.101663 9.101663 ZT4-7 7.554281 7.554281 7.554281 ZT8-11 8.934542 8.934542 8.934542 ZT12-15 11.400699 11.400699 11.400699 ZT16-19 10.302315 10.302315 10.302315 ZT20-23 9.619152 9.619152 9.619152