condition mean min max ZT0-3 345.710314 345.710314 345.710314 ZT4-7 488.554573 488.554573 488.554573 ZT8-11 670.976735 670.976735 670.976735 ZT12-15 938.8141825 938.8141825 938.8141825 ZT16-19 1062.244087 1062.244087 1062.244087 ZT20-23 1001.8898730000001 1001.8898730000001 1001.8898730000001