condition mean min max ZT0-3 693.761093 693.761093 693.761093 ZT4-7 635.3052574999999 635.3052574999999 635.3052574999999 ZT8-11 642.9457595 642.9457595 642.9457595 ZT12-15 698.7568345 698.7568345 698.7568345 ZT16-19 771.3191575 771.3191575 771.3191575 ZT20-23 870.798149 870.798149 870.798149