I'm confused

My car (MY00 UK Turbo) had its 48 month service last December in which the plugs were changed as per Subaru's requirements. Its now due its 60 month service and according to the book the plugs need to be changed again I've only done about 7000 miles on the last set, is it really necessary to have them changed again, or have I read the service book wrong

 

hi there the plugs need to be changed service says1 year or so many miles do you want to take the chance these cars are not like other cars so i would if it was mine i change tham on mine hope that helps