indicators of statistical properties

[Leonard Soicher]

Dear All,

I shall soon be programming the indicators for the GAP Writer.

Two, however, might reasonably go under <statistical_properties>. 
They are:

    element variance_balanced {
	attribute value { xsd:boolean }
    } ?
    ,
    element efficiency_balanced {
	attribute value { xsd:boolean }
    } ?

What do you think JP? Should you/do you want to do these?
Also, should one or both of these have the value "not_applicable" 
when the design is not connected?

Regards,  Leonard