Capital Gains: Are separate improvements taken to be a single improvement for subsection 160P(6) purposes?

Are separate improvements taken to be a single improvement for section 160P(6) purposes?

Taxation Determination TD 6 is withdrawn with effect from today. It is replaced by Taxation Determination TD 95/58 'Income tax: capital gains: in determining whether the threshold and ratio tests in subsection 160P(6) of the Income Tax Assessment Act 1936 are met, in what circumstances is it appropriate to aggregate a number of enhancements made to an asset so as to constitute an "improvement" to the asset?'