condition mean min max ZT0-3 10.424916666666666 8.00721 12.917449999999999 ZT4-7 8.13261 8.13261 8.13261 ZT8-11 6.406264999999999 6.406264999999999 6.406264999999999 ZT12-15 7.8763325 6.574945 9.17772 ZT16-19 6.36299 6.36299 6.36299 ZT20-23 9.17059 9.17059 9.17059