condition mean min max ZT0-3 0.68735989 0.628330838 0.7463889419999999 ZT4-7 0.9884253672499999 0.889896516 1.0869542184999998 ZT8-11 0.5751129895 0.539459771 0.610766208 ZT12-15 1.0378021375 1.0119266615 1.0636776135 ZT16-19 1.397304111 1.2020832625 1.5925249595 ZT20-23 2.37691860925 2.3001084865 2.453728732