condition mean min max ZT0-3 0.3009895 0.174392 0.39035000000000003 ZT4-7 0.0 0.0 0.0 ZT8-11 0.2274355 0.2274355 0.2274355 ZT12-15 0.29239824999999997 0.288901 0.2958955 ZT16-19 0.21407400000000001 0.21407400000000001 0.21407400000000001 ZT20-23 0.301373 0.301373 0.301373