condition mean min max ZT0-3 228.744098 228.744098 228.744098 ZT4-7 259.7098025 259.7098025 259.7098025 ZT8-11 271.2319725 271.2319725 271.2319725 ZT12-15 289.64630999999997 289.64630999999997 289.64630999999997 ZT16-19 275.6346975 275.6346975 275.6346975 ZT20-23 359.41359 359.41359 359.41359