condition mean min max ZT0-3 254.997478 254.997478 254.997478 ZT4-7 457.844016 457.844016 457.844016 ZT8-11 318.091668 318.091668 318.091668 ZT12-15 200.125605 200.125605 200.125605 ZT16-19 64.91895550000001 64.91895550000001 64.91895550000001 ZT20-23 52.879515 52.879515 52.879515