condition mean min max ZT0-3 8.829821666666668 8.62587 8.956245 ZT4-7 5.8545300000000005 5.8545300000000005 5.8545300000000005 ZT8-11 2.67572 2.67572 2.67572 ZT12-15 0.98898025 0.6009055000000001 1.377055 ZT16-19 0.5334574999999999 0.5334574999999999 0.5334574999999999 ZT20-23 2.2943499999999997 2.2943499999999997 2.2943499999999997