condition mean min max ZT0-3 1.1666551666666667 0.257757 1.803155 ZT4-7 0.3361855 0.3361855 0.3361855 ZT8-11 0.063433 0.063433 0.063433 ZT12-15 0.2584695 0.1629565 0.35398250000000003 ZT16-19 0.5423910000000001 0.5423910000000001 0.5423910000000001 ZT20-23 1.016059 1.016059 1.016059