condition mean min max ZT0-3 4.2146825 4.104005 4.32536 ZT4-7 3.964305 3.964305 3.964305 ZT8-11 2.526247 2.526247 2.526247 ZT12-15 0 0 0 ZT16-19 7.37476 7.37476 7.37476 ZT20-23 4.33367 4.33367 4.33367