condition mean min max ZT0-3 1.959585 1.79635 2.12282 ZT4-7 2.12432 2.12432 2.12432 ZT8-11 4.05949 4.05949 4.05949 ZT12-15 0 0 0 ZT16-19 5.009925 5.009925 5.009925 ZT20-23 3.097785 3.097785 3.097785