condition mean min max ZT0-3 13.291517 13.291517 13.291517 ZT4-7 12.9200435 12.9200435 12.9200435 ZT8-11 12.871936999999999 12.871936999999999 12.871936999999999 ZT12-15 12.263183 12.263183 12.263183 ZT16-19 15.4488975 15.4488975 15.4488975 ZT20-23 12.293441999999999 12.293441999999999 12.293441999999999