condition mean min max ZT0-3 7.756335 6.922205 8.590465 ZT4-7 6.007665 6.007665 6.007665 ZT8-11 2.7042200000000003 2.7042200000000003 2.7042200000000003 ZT12-15 0 0 0 ZT16-19 4.8583300000000005 4.8583300000000005 4.8583300000000005 ZT20-23 5.2250049999999995 5.2250049999999995 5.2250049999999995