Considering only comparable fare classifications, which classifications offer the greatest percentage difference between air travel and ship travel?

travel type sample round-trip fares from new york to london
first-class air fare $754.30
first-class ship fare $775.20
regular economy air fare $440.80
tourist class ship fare $408.00
peak season economy air fare $526.30
peak season tourist class ship fare $470.25
14- to 21-day excursion air fare $331.00
30-day excursion ship fare $345.95
charter group (25 persons or more) air fare $331.00
charter group (25 persons or more) ship fare $306.00
regular economy air fare - tourist class ship fare would be $.

the percentage difference would be %.

peak season economy air fare - peak season tourist ship fare = $

the percentage difference would be %.

charter group air fare - charter group ship fare = $

the percentage difference would be %.

therefore, the peak-season classification offers the greatest percentage difference at %.