condition mean min max ZT0-3 5.17377032975 1.8124765195 8.53506414 ZT4-7 3.58794745575 2.7739622895 4.401932622 ZT8-11 5.5504029035 4.1816209675 6.9191848395 ZT12-15 8.099122980499999 7.5796775555 8.6185684055 ZT16-19 10.1381651885 8.579253002 11.697077375 ZT20-23 15.9431692 13.26557191 18.62076649