I should have mentioned that the bold text in the quote from the Report
is my emphasis.  Also I divided the cost of replacement trams by 271 -
the number of high floor cars to go, whereas if DOT is replacing 1.2 old
trams by 1 new tram, the cost per tram is a bit more than $6.99 each.   
But to keep to reasonable headways, and bearing in mind increasing
traffic congestion - which the Report mentions- the trams should be
replaced on a one for one basis at least.

regards

Dudley