Clarification of Weekly Mileage in Taper

In the L1 program week 18 narrative I see a recommendation to cut mileage by 20 to 30% vs week 17 peak mileage, but the sample mileage charts don’t drop by quite that much. For example I’ve been following the 50 and 55 miles charts, which show drops of 50 to 47 and 55 to 52 respectively. Just clarifying, should I follow the narrative advice and cut 55 miles last week to the low 40’s?