condition mean min max ZT0-3 3.887255 3.7192350000000003 4.055275 ZT4-7 5.102964999999999 5.102964999999999 5.102964999999999 ZT8-11 3.258875 3.258875 3.258875 ZT12-15 0 0 0 ZT16-19 4.565815000000001 4.565815000000001 4.565815000000001 ZT20-23 5.024785 5.024785 5.024785