In 1751 the numbering of the Regiments (this ranking was already fixed in 1742) became the official way to designate them and the use of the name of their colonels was abolished. This numbering was used until the reforms of 1922.
During several great conflicts (like the American Revolution and the wars of the coalition) the army was greatly expanded and then reduced again. This lead to numbers of the Dragoon regiments used several times in history.
Below a list of numbered regiments and the periods in history they existed.
Please not that the 1st - 25th Regiments of Dragoons already had their ranking before it was fixed in 1742 and that regiments may also have an existence before or after the given period under a different number.
Also note that while many Dragoons changes their type to Hussars and Lancers, this had no influence on their regimental numbers.