condition mean min max ZT0-3 10.9640475 10.234494999999999 11.6936 ZT4-7 11.05935 11.05935 11.05935 ZT8-11 2.50759 2.50759 2.50759 ZT12-15 0 0 0 ZT16-19 2.57511 2.57511 2.57511 ZT20-23 8.95285 8.95285 8.95285