From PHB.
With their unearthly grace and fine features, elves
appear hauntingly beautiful to humans and members
of many other races. They are shorter than
humans on average, ranging from well under 5 feet
tall to just over 6 feet. They are more slender than
humans, weighing only 100 to 145 pounds. Males and
females are about the same height, and males are only
marginally heavier than females.
Elves’ coloration encompasses the normal human
range and also includes skin in shades of copper,
bronze, and almost bluish-white, hair o f green or blue,
and eyes like pools o f liquid gold or silver. Elves have no
facial and little body hair. They favor elegant clothing in
bright colors, and they enjoy simple yet lovely jewelry.
"On average", "over 6 feet" and that's the description to the race as a whole, no subraces. So on average they maybe shorter, but it doesn't mean that every single subrace is shorter. Having 2(wood, drow) out of 3 subraces shorter will be shorter on average. And it says that they can be over 6 feet.
