condition mean min max ZT0-3 5.141491666666667 4.00016 5.80246 ZT4-7 4.41006 4.41006 4.41006 ZT8-11 4.203609999999999 4.203609999999999 4.203609999999999 ZT12-15 4.5505475 4.153245 4.947850000000001 ZT16-19 4.53399 4.53399 4.53399 ZT20-23 6.744305000000001 6.744305000000001 6.744305000000001