condition mean min max ZT0-3 2.899165 2.4751250000000002 3.3232049999999997 ZT4-7 1.842835 1.842835 1.842835 ZT8-11 0.585367 0.585367 0.585367 ZT12-15 0 0 0 ZT16-19 1.82911 1.82911 1.82911 ZT20-23 1.8897499999999998 1.8897499999999998 1.8897499999999998