Update v2.2.md

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versions/v2.2.md

@@ -255,4 +255,4 @@ The model provides the following consumer-response hypotheses, which can be used
 | buy_new                | Buy vehicle of highest available standard. The fuel composition of that vehicle corresponds to the share of the respective sales during the year of LEZ implementation.                                                                                                                                                                                |
 | buy_used               | Buy used vehicles (in the same manner as in the natural turnover). The fuel composition of that vehicle corresponds to the share of the fleet during the year of LEZ implementation. The age of the installed vehicles follows a poisson distribution around the average entry age of used vehicles limited by the oldest available standard.          |
 
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