The stats are a bit misleading. Of course the sales for Jan 2017 will be low if it was known beforehand that Q4 2016 would be the last moment that electric cars were not fully taxed. Everyone who was planning to purchase an electric car would make sure to buy it in Q4 2016 and not in Q1 2017.

This doesn't tell much about the future of electric cars sales in Denmark; after a while the sales will recover again and only then we will know if they have dropped comparing to the earlier numbers or not.