What is normal liver function?

Liver function includes many items, among which the normal values of several important items are: serum total protein 60-80g/L, alanine aminotransferase 5-40 U/L, aspartate aminotransferase 8-40U/L, alkaline phosphatase 40-110 U, total bilirubin 1.71-17.1μmol/L, direct bilirubin 1.71-7μmol/L, indirect bilirubin 1.7-13.7μ mol/L, glutamyl transferase less than 40u, blood ammonia 20 - 60μmol/L, Alpha-fetoprotein is less than 30μmg/L.