 Complete the following phrase:  The circuit was criticised by drivers for its lack of overtaking opportunities. Changes in Formula One in 2011, including the introduction of the Drag Reduction System and the switch to Pirelli tyres, partially improved that with 27 passes recorded in that years race, 22 of which were accredited to the assistance of DRS. However, the five normal overtakes still represented the years second lowest total, although the adoption of two DRS zones for that years race limited the potential for non-DRS assisted passes. Despite this, 