condition mean min max ZT0-3 4.5611049999999995 3.4992349999999997 6.216265 ZT4-7 3.42861 3.42861 3.42861 ZT8-11 4.51309 4.51309 4.51309 ZT12-15 5.6340125 4.694134999999999 6.5738900000000005 ZT16-19 4.31945 4.31945 4.31945 ZT20-23 4.24563 4.24563 4.24563