condition mean min max ZT0-3 2.6740375 2.56363 2.784445 ZT4-7 2.661175 2.661175 2.661175 ZT8-11 3.79617 3.79617 3.79617 ZT12-15 0 0 0 ZT16-19 3.166115 3.166115 3.166115 ZT20-23 3.508505 3.508505 3.508505