Specify a value between 0 and 1 to indicate the cumulative proportion of variation to be explained by the principal components . The proportion entered here indirectly determines the number of principal components used to adjust the association tests.The number of displayed principal components is determined either by the result of a calculation involving this proportion, or the Maximum Number of Principal Components to Model , whichever is smaller, except when the Maximum Number of Principal Components to Model parameter is disabled by setting it to 0 (in which case, the Maximum Number of Principal Components to Model parameter is ignored ).Note : This option is enabled only when the Correlation and Principal Variance Components Analysis box is checked.