 The team presentation took place in <unk> on the evening before the first stage . The number of riders allowed per squad was nine , therefore the start list contained a total of 198 riders . The riders represented 37 different countries , with the largest numbers coming from France ( 30 ) , Spain ( 27 ) and Italy ( 20 ) . The average age of riders in the Vuelta was 29 @.@ 13 years , ranging from the 20 @-@ year @-@ old Matej Mohorič ( Cannondale – Garmin ) to the 38 @-@ year @-@ old Haimar Zubeldia ( Trek Factory Racing ) . 
