condition mean min max ZT0-3 2.868088333333333 1.92427 4.51609 ZT4-7 3.440085 3.440085 3.440085 ZT8-11 2.19891 2.19891 2.19891 ZT12-15 2.96802 2.75012 3.1859200000000003 ZT16-19 2.44367 2.44367 2.44367 ZT20-23 2.57337 2.57337 2.57337