condition mean min max ZT0-3 1.9976425 1.28138 2.713905 ZT4-7 2.8022600000000004 2.8022600000000004 2.8022600000000004 ZT8-11 4.133255 4.133255 4.133255 ZT12-15 0 0 0 ZT16-19 4.91097 4.91097 4.91097 ZT20-23 5.199375 5.199375 5.199375