condition mean min max ZT0-3 4.732695 4.732695 4.732695 ZT4-7 2.49834 2.49834 2.49834 ZT8-11 7.993195 7.993195 7.993195 ZT12-15 17.146549999999998 17.146549999999998 17.146549999999998 ZT16-19 14.63355 14.63355 14.63355 ZT20-23 9.99952 9.99952 9.99952