According to [0] from 2000, about 8% of the greenhouses in Almeria, Spain use hydroponics. [1] from 2010 says it's now 10%. The pictures in [2] show that 10% is still a lot...
[0] http://www.schundler.com/spain.htm
[1] http://books.google.com/books?id=5Ag-wT0rLEMC&pg=PA47&lpg=PA...
[2] http://www.amusingplanet.com/2013/08/the-greenhouses-of-alme...