From the Introduction: "The Navy has been procuring F/A-18E/F Super Hornet strike fighters since FY1997. Super Hornets and older F/A-18A/B/C/D Hornets currently account for the majority of the aircraft in the Navy's 10 active-duty aircraft carrier air wings (CVWs)--of the 70 or so aircraft in each CVW, more than 40 typically are Hornets and Super Hornets. In FY2006, the Navy also began procuring the EA-18G Growler, an electronic warfare version of the Super Hornet. Growlers are replacing older Navy and Marine Corps EA-6B Prowler electronic attack aircraft. Super Hornets and Growlers were procured in FY2005-FY2009 under a multiyear procurement (MYP) arrangement. The Navy's proposed FY2012 budget requests about $2.4 billion for the procurement of 28 F/A-18E/F Super Hornet strike fighters and about $1.1 billion for the procurement of 12 EA-18G Growler electronic attack aircraft. The Navy's FY2011 request for 22 F/A-18E/Fs comes in the context of a projected shortfall in Navy and Marine Corps strike fighters. Estimates of the extent of the shortfall vary, with the peak of the shortfall ranging from 100 aircraft by one estimate to 243 or more aircraft according to other estimates."
CRS Report for Congress, RL30624