20 For all ship types to which these guidelines
apply except for ro-ro passenger ships, parameters "a" and "c" are
determined from a regression analysis undertaken by plotting the calculated
estimated index values against 100 per cent deadweight (100% DWT).
21 For ro-ro passenger ships, parameters "a" and
"c" are determined from a regression analysis undertaken by plotting
the calculated estimated index values against corrected deadweight,
DWT, for ships to which the capacity correction factor, fcRoPax
, applies and against 100 per cent deadweight (100% DWT)
for ships to which the capacity correction factor does not apply.