With reference to the table below, calculate the three-firm concentration ratio for the offshore wind generation market in Sector Gamma. Show your workings and express your answer to two decimal places.
| Operator | Generation Capacity (MW) |
|---|---|
| VentiPower | 1480 |
| NordAura | 1220 |
| SolasEnergy | 960 |
| ZephyrGen | 340 |
| OceanBreeze | 210 |
| AeolusLtd | 180 |
| Independent local co-operatives | 690 |