condition mean min max ZT0-3 6.4197299999999995 3.271595 9.567865 ZT4-7 0.9187535 0.9187535 0.9187535 ZT8-11 2.11246 2.11246 2.11246 ZT12-15 0 0 0 ZT16-19 1.4907050000000002 1.4907050000000002 1.4907050000000002 ZT20-23 0.324992 0.324992 0.324992