2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

Jan

$2.555

$4.988

$6.150

$6.213

$11.431

$5.838

$7.172

$6.136

$5.814

$4.216

$3.084

Feb

$2.006

$5.660

$5.775

$6.288

$8.400

$6.917

$7.996

$4.476

$5.274

$4.316

$2.678

Mar

$2.388

$9.133

$5.150

$6.304

$7.112

$7.547

$8.930

$4.056

$4.816

$3.793

Apr

$3.472

$5.146

$5.365

$7.323

$7.233

$7.558

$9.578

$3.631

$3.842

$4.240

May

$3.319

$5.123

$5.935

$6.748

$7.198

$7.508

$11.280

$3.321

$4.271

$4.377

Jun

$3.420

$5.945

$6.680

$6.123

$5.925

$7.591

$11.916

$3.538

$4.155

$4.326

Jul

$3.278

$5.291

$6.141

$6.976

$5.887

$6.929

$13.105

$3.949

$4.717

$4.357

Aug

$2.976

$4.693

$6.048

$7.647

$7.042

$6.110

$9.217

$3.379

$4.774

$4.377

Sep

$3.288

$4.927

$5.082

$10.847

$6.816

$5.430

$8.394

$2.843

$3.651

$3.857

Oct

$3.686

$4.430

$5.723

$13.907

$4.201

$6.423

$7.472

$3.730

$3.837

$3.759

Nov

$4.126

$4.459

$7.626

$13.832

$7.153

$7.269

$6.469

$4.289

$3.292

$3.524

Dec

$4.140

$4.860

$7.976

$11.180

$8.318

$7.203

$6.888

$4.486

$4.267

$3.364