condition mean min max ZT0-3 4.614179999999999 4.24069 4.98767 ZT4-7 6.16025 6.16025 6.16025 ZT8-11 7.888 7.888 7.888 ZT12-15 0 0 0 ZT16-19 8.942654999999998 8.942654999999998 8.942654999999998 ZT20-23 6.3729700000000005 6.3729700000000005 6.3729700000000005