condition mean min max ZT0-3 6.408738707 4.255453503 8.562023911 ZT4-7 2.7742888015 2.532474123 3.01610348 ZT8-11 6.606018596999999 4.1397580975 9.072279096499999 ZT12-15 6.15415699125 4.97313075 7.3351832325 ZT16-19 3.53888367425 3.070519482 4.0072478665 ZT20-23 2.54817004525 1.8158204235 3.280519667