condition mean min max ZT0-3 21.544150000000002 19.740850000000002 23.347450000000002 ZT4-7 11.33295 11.33295 11.33295 ZT8-11 6.3445350000000005 6.3445350000000005 6.3445350000000005 ZT12-15 0 0 0 ZT16-19 10.214755 10.214755 10.214755 ZT20-23 15.43285 15.43285 15.43285