condition mean min max ZT0-3 10.422636666666666 5.785159999999999 13.02665 ZT4-7 3.721965 3.721965 3.721965 ZT8-11 3.661275 3.661275 3.661275 ZT12-15 9.354305 8.25641 10.452200000000001 ZT16-19 11.3947 11.3947 11.3947 ZT20-23 14.77355 14.77355 14.77355