condition mean min max ZT0-3 6.686035 6.686035 6.686035 ZT4-7 4.17604 4.17604 4.17604 ZT8-11 5.49644 5.49644 5.49644 ZT12-15 7.4991699999999994 7.4991699999999994 7.4991699999999994 ZT16-19 10.57366 10.57366 10.57366 ZT20-23 7.677630000000001 7.677630000000001 7.677630000000001