condition mean min max ZT0-3 15.18935 14.1433 16.2354 ZT4-7 24.55395 24.55395 24.55395 ZT8-11 24.16035 24.16035 24.16035 ZT12-15 0 0 0 ZT16-19 21.606 21.606 21.606 ZT20-23 22.2442 22.2442 22.2442