condition mean min max ZT0-3 9.485471666666667 6.62834 12.558150000000001 ZT4-7 7.88068 7.88068 7.88068 ZT8-11 7.213865 7.213865 7.213865 ZT12-15 15.984224999999999 13.57185 18.3966 ZT16-19 12.224599999999999 12.224599999999999 12.224599999999999 ZT20-23 8.870035 8.870035 8.870035