The principal inertias of a Burt table in Multiple Correspondence Analysis are the eigenvalues. The problem with these inertias is that they provide a pessimistic indication of fit. Benzécri proposed an inertia adjustment. Greenacre argued that the Benzécri adjustment overestimates the quality of fit and proposed an alternate adjustment. Both adjustments are calculated for your reference. See Statistical Details for Adjusted Inertia.
Inertia
Lists the square of the singular values, reflecting the relative variation accounted for in the canonical dimensions.
Adjusted Inertia
Lists the adjusted inertia according to either the Benzécri or Greenacre adjustment.
Percent
Portion of adjusted inertia with respect to the total inertia.
Cumulative Percent
Shows the cumulative portion of adjusted inertia. If the first two singular values capture the bulk of the inertia, then the 2-D correspondence analysis plot is sufficient to show the relationships in the table.