condition mean min max ZT0-3 5.47398 5.47398 5.47398 ZT4-7 9.48575 9.48575 9.48575 ZT8-11 2.59333 2.59333 2.59333 ZT12-15 12.596455 12.596455 12.596455 ZT16-19 8.357725 8.357725 8.357725 ZT20-23 3.10753 3.10753 3.10753