condition mean min max ZT0-3 6.40411 4.91639 7.891830000000001 ZT4-7 6.832045000000001 6.832045000000001 6.832045000000001 ZT8-11 5.057315 5.057315 5.057315 ZT12-15 0 0 0 ZT16-19 6.620665000000001 6.620665000000001 6.620665000000001 ZT20-23 8.448745 8.448745 8.448745