condition mean min max ZT0-3 6.2735199999999995 6.2735199999999995 6.2735199999999995 ZT4-7 3.6585 3.6585 3.6585 ZT8-11 3.34229 3.34229 3.34229 ZT12-15 4.52929 4.52929 4.52929 ZT16-19 7.4306350000000005 7.4306350000000005 7.4306350000000005 ZT20-23 6.099270000000001 6.099270000000001 6.099270000000001