condition mean min max ZT0-3 0.778621 0.5621015 1.0287215 ZT4-7 1.0428475 1.0428475 1.0428475 ZT8-11 0.6928835 0.6928835 0.6928835 ZT12-15 0.7906225 0.6204784999999999 0.9607665 ZT16-19 0.367908 0.367908 0.367908 ZT20-23 1.0697510000000001 1.0697510000000001 1.0697510000000001