Why are numbers rounded when I import data?

When an attribute of the type decimal Attribute type that stores a fixed precision, floating-point value., money Attribute type that stores positive or negative numbers between -922,337,203,685,477 and 922,337,203,685,477. Decimal places are supported between 0 and 4 digits after the decimal., or float Attribute type that stores positive or negative numbers between -100,000,000,000 and 100,000,000,000. Decimal places are supported between 0 and 5 digits after the decimal. is created in Microsoft Dynamics CRM Online, the precision, or number of decimals, is defined. If the number of decimals in the source data is more than the number that is specified for the attribute in Microsoft Dynamics CRM Online, the imported floating-point data is rounded to the number of decimals defined in the attribute definition. The precision value cannot be changed after an attribute is created.