Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Year | World Car of the Year | World Performance Car | World Green Car | World Car Design of the Year |
| --- | --- | --- | --- | --- |
| 2006 | BMW 3-Series (winner)\nMazda MX-5\nPorsche Cayman S\n\n\n\nBMW 1-Series\nHonda Civic and Honda Civic Hybrid\nLand Rover Range Rover Sport\nLexus IS\nMercedes-Benz M-Class\nMercedes-Benz S-Class\nSuzuki Swift\nVolkswagen Passat | Porsche Cayman S (winner)\nAudi RS4\nBMW M5\n\n\n\nAston Martin V8 Vantage\nBMW 130i MSport\nBMW M6\nBugatti Veyron 16.4\nChrysler 300C SRT-8 | Honda Civic Hybrid (winner)\nCitroën C1 1.4 Hdi Diesel\nLexus RX 400h\n\n\n\nBMW 325Ci | Citroën C4 (winner)\nBMW 3-Series\nHonda Civic\n\n\n\nAston Martin V8 Vantage\nBMW 1 Series |
| 2007 | Lexus LS 460 (winner)\nMINI\nAudi TT\n\n\n\nAudi Q7\nBMW Z4\nCitroën C4 Picasso\nCitroën C6\nFiat Grande Punto\nFiat Sedici / Suzuki SX4\nJaguar XK\nMercedes CL | Audi RS4 (winner)\nBMW 335i\nPorsche 911 Turbo\n\n\n\nAudi S6\nBMW Z4/Z4 M\nFerrari 599 GTB Fiorano\nJaguar XKR\nMazda 3 MPS / Mazdaspeed3\nPorsche 911 GT3\nRenault Clio Renault Sport | Mercedes-Benz E320 Bluetec (winner)\nBMW Hydrogen 7-Series\nVolkswagen Polo GTI BlueMotion | Audi TT (winner)\nCitroën C4 Picasso\nFiat Grande Punto |
| 2008 | Mazda2 / Demio (winner)\nFord Mondeo\nMercedes-Benz C-Class\n\n\n\nAudi A5/S5\nAudi R8\nCadillac CTS\nFord S-Max\nNissan Qashqai/Dualis\nNissan Skyline Coupe/Infiniti G37 Coupe\nVolvo C30 | Audi R8 (winner)\nAudi S5 Coupé\nBMW M3\n\n\n\nMercedes-Benz CL 63 AMG\nMercedes-Benz S 63 AMG\nAston Martin V8 Vantage Roadster\nHonda Civic Type R\nMaserati GranTurismo\nMercedes-Benz CLK63 AMG Black Series\nRenault Clio F1 Team R27 | BMW 118d (winner)\nSmart Fortwo cdi\nVolkswagen Passat 1.9 TDI\n\n\n\nChevrolet Equinox Fuel Cell Electric Vehicle\nChevrolet Malibu Hybrid\nChevrolet Tahoe/GMC Yukon Hybrids\nLexus LS 600h L\nNissan Altima Hybrid\nSaturn Aura Green Line\nSaturn Vue Green Line | Audi R8 (winner)\nMazda2\nVolvo C30\n\n\n\nAudi R8 Coupe / Roadster |
| 2009 | Volkswagen Golf (winner)\nFord Fiesta\nToyota iQ | Nissan GT-R (winner)\nChevrolet Corvette ZR1\nPorsche 911 | Honda FCX Clarity (winner)\nToyota iQ\nMitsubishi i MiEV | Fiat 500 (winner)\nJaguar XF\nCitroën C5 |
| 2010 | Volkswagen Polo (winner)\nMercedes-Benz E-Class\nAudi A5\n\n\n\nChevrolet Cruze\nKia Soul\nMazda 3 | Audi R8 V10 (winner)\nFerrari California\nPorsche 911 GT3\n\n\n\nAston Martin V12 Vantage\nAudi TT RS Coupé / Roadster\nBMW Z4\nJaguar XFR\nMercedes-Benz E63 AMG\nNissan 370Z | Volkswagen BlueMotion (winner)\nHonda Insight\nToyota Prius\n\n\n\nFord Fusion Hybrid\nMercedes-Benz S400 BlueHybrid | Chevrolet Camaro (winner)\nCitroën C3 Picasso\nKia Soul\n\n\n\nToyota Prius |
| 2011 | Nissan Leaf (winner)\nAudi A8\nBMW 5 Series\n\n\n\nAudi A1\nBMW X3\nJaguar XJ\nJeep Grand Cherokee\nMercedes-Benz SLS\nPorsche Cayenne\nVolvo S60 / V60 | Ferrari 458 Italia (winner)\nMercedes-Benz SLS AMG\nPorsche 911 Turbo\n\n\n\nAston Martin Rapide\nAudi RS5\nCadillac CTS-V\nLamborghini Gallardo SUPERLEGGERA\nMercedes-Benz CL63 AMG\nPorsche 911 GT2RS\nRenault Mégane III / Renault Sport | Chevrolet Volt (winner)\nBMW 320d EfficientDynamics Edition\nNissan Leaf\n\n\n\nHyundai Sonata Hybrid\nMercedes-Benz B-Class F-Cell\nsmart electric drive | Aston Martin Rapide (winner)\nAlfa Romeo Giulietta\nFerrari 458 Italia\n\n\n\nAudi A7\nCitroën DS3\nHonda CR-Z\nKia Sportage\nNissan Juke |
| 2012 | Volkswagen up! (winner)\nBMW 3 Series\nPorsche 911\n\n\n\nAudi A6\nAudi Q3\nBMW 1 Series\nChevrolet Volt / Opel/Vauxhall Ampera\nCitroën DS5\nFord Focus\nRange Rover Evoque | Porsche 911 (winner)\nLamborghini Aventador\nMcLaren MP4-12C\n\n\n\nAudi RS 3 Sportback\nBMW 1 Series M Coupé\nBMW M5\nChevrolet Camaro ZL1\nFerrari FF\nMercedes-Benz C-63 Coupe AMG Black Series\nMercedes-Benz CLS 63 AMG | Mercedes-Benz S250 CDI BlueEFFICIENCY (winner)\nFord Focus Electric\nPeugeot 3008 HYbrid4\n\n\n\nMitsubishi i\nRenault Fluence ZE | Range Rover Evoque (winner)\nVolkswagen up!\nCitroën DS5\n\n\n\nHyundai Veloster\nPorsche 911 |
| 2013 | Volkswagen Golf (winner)\nMercedes-Benz A-Class\nPorsche Boxster / Cayman\nScion FR-S/Subaru BRZ/Toyota GT-86\n\n\n\nAudi A3\nLand Rover Range Rover\nMazda CX-5\nMazda6\nPeugeot 208\nVolvo V40 | Porsche Boxster / Cayman (winner)\nScion FR-S/Subaru BRZ/Toyota GT-86\nFerrari F12 Berlinetta\n\n\n\nAston Martin Vanquish\nAudi RS5\nBMW M6\nBMW M135i\nMercedes SL63 AMG\nMercedes SLS AMG Roadster\nRenaultsport Clio 200 EDC | Tesla Model S (winner)\nRenault Zoe\nVolvo V60 Plug-in Hybrid\n\n\n\nSmart Electric Drive\nVolkswagen Jetta Hybrid | Jaguar F-Type (winner)\nAston Martin Vanquish\nMazda6\n\n\n\nRange Rover\nRenault Clio\nVolkswagen Golf |
Question:
what is the average number of winners each year?
Answer:
4