Order of Parameters

I've been working on a project in which I retrieve all of the Instance and Type Parameters from an object and I've noticed something odd.

foreach (Parameter para in eCoreWall.Parameters)
{
  results += Util.GetParameterInformation(para, m_doc);
} 

Each time I pull the parameters, they are listed in a different order.  Anyone know why?
Here's an abbreviated example:

1st Time- 
Area: 27.72 SF
Length: 59.00
Function: Exterior


2nd Time-
Length: 59.00
Area: 27.72 SF
Function: Exterior