What percentage savings does a person obtain on a round-trip ticket from new york to london if he chooses to go 14- to 21-day excursion air fare as opposed to regular economy air fare?

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