Complex sentence: In 2011-2012 the training fields was modernized, and 2 more were build, so now there is 4 training fields with lighting, 2 with grass 2 with artificial-grass.
Split into simpler sentences: In 2011-2012 the training fields was modernized, and 2 more were built. Currently, there are 4 training fields with lighting, 2 with natural grass and 2 with artificial-grass.