condition mean min max ZT0-3 6.513213333333333 1.861895 9.52273 ZT4-7 1.275185 1.275185 1.275185 ZT8-11 1.45509 1.45509 1.45509 ZT12-15 3.4390600000000004 2.07835 4.7997700000000005 ZT16-19 6.300895000000001 6.300895000000001 6.300895000000001 ZT20-23 9.999925000000001 9.999925000000001 9.999925000000001