condition mean min max ZT0-3 10.276245 9.184285 11.368205 ZT4-7 27.411500000000004 27.411500000000004 27.411500000000004 ZT8-11 37.0587 37.0587 37.0587 ZT12-15 0 0 0 ZT16-19 20.20165 20.20165 20.20165 ZT20-23 23.764899999999997 23.764899999999997 23.764899999999997