20. Selected Quarterly Financial Data (unaudited) 2009  2010 (in thousands except per share amounts)  Q1  Q2  Q3  Q4  Q1  Q2  Q3  Q4 Revenue  $116,732  $119,533  $120,088  $122,643  $128,290  $ 136,091  $ 139,817  $ 151,153 Total operating expense (1) (2)  82,144   87,382  86,441  98,356  97,348   108,424   109,656   118,864 Operating income (2)   34,588  32,151  33,647  24,287  30,942  27,667  30,161   32,289 Non-operating income (expense), net  534  1,972  793  (365)  (179)  21  6,206  684 Income before income taxes and equity in net  35,122  34,123  34,440  23,922  30,763  27,688  36,367   32,973 income of unconsolidated entities (2) Income tax expense (2)  10,755  13,956  12,493  9,571  10,995  10,225  11,917  9,619 Equity in net income (loss) of  382  (21)  429  375  389  454  333  246 unconsolidated entities Consolidated net income (2)   24,749  20,146  22,376  14,726  20,157  17,917  24,783   23,600 Net (income) loss attributable to  89  (71)  22  92  31  85  (106)  (97) the noncontrolling interests Net income attributable to  $ 24,838  $ 20,075  $ 22,398  $ 14,818  $ 20,188  $ 18,002  $ 24,677  $ 23,503 Morningstar, Inc. (2) Basic net income per share:  Basic net income per share attributable  $  0.52  $  0.42  $  0.46  $  0.30  $  0.41  $  0.37  $  0.50  $  0.47 to Morningstar, Inc. (2) Weighted average common   47,378  47,941  48,457  48,652  48,828  49,234  49,401   49,523 shares outstanding—basic Diluted net income per share:  Diluted net income per share attributable  $  0.51  $  0.40  $  0.45  $  0.29  $  0.40  $  0.36  $  0.49  $  0.46 to Morningstar, Inc. (2) Weighted average common  49,167  49,631  50,048  50,248  50,332  50,533  50,544  50,761 shares outstanding—diluted (1) Includes stock-based  compensation expense of:  $ 2,725  $ 3,068  $  2,863  $  2,937  $  2,937  $  3,655  $  3,745  $ 3,456 Morningstar, Inc. 2010 Annual Report 137