| Revenues | — | — | — |
| Research | 5,125.65a | 4,887.05a | 4,604.79a |
| Conferences | 583.22a | 505.16a | 389.27a |
| Consulting | 558.54a | 514.75a | 481.78a |
| Total revenues | 6,267.41a | 5,906.96a | 5,475.85a |
| Costs and expenses | — | — | — |
| Cost of services and product development | -2,023.02a | -1,903.24a | -1,693.77a |
| Selling, general and administrative | -2,884.81a | -2,701.54a | -2,480.94a |
| Depreciation | -112.08a | -98.65a | -93.41a |
| Amortization of intangibles | -90.23a | -92.46a | -98.54a |
| Acquisition and integration charges | -0.97a | -9.59a | -9.08a |
| Gain from sale of divested operation | 0a | -135.41a | 0a |
| Total costs and expenses | -5,111.12a | -4,670.06a | -4,375.74a |
| Operating income | 1,156.29a | 1,236.89a | 1,100.11a |
| Interest income | 61.56a | 38.53a | 4.88a |
| Interest expense | -131.05a | -132.77a | -126.2a |
| Gain on event cancellation insurance claims | 300a | 3.08a | 0a |
| Other income, net | 0.58a | 1.4a | 48.41a |
| Income before income taxes | 1,387.37a | 1,147.13a | 1,027.2a |
| Provision for income taxes | -133.66a | -264.66a | -219.4a |
| Net income | 1,253.72a | 882.47a | 807.8a |