There are about 30,000 Knights and Dames worldwide, articulated within geographic areas through local organizations called Lieutenancies or Magistral Delegations (which are often the first step towards the formation of a Lieutenancy).
From the Order's Constitution:
“The life of the Order is articulated in the individual nations through local organizations, called Lieutenancies or Magistral Delegations, upon which Sections and Local Delegations depend.”
“The Lieutenancies and the Magistral Delegations insure, within the boundaries of the respective territorial jurisdictions, respect for the Constitution and the norms of the Order, and also the exact fulfillment of the directives imparted by the Cardinal Grand Master, by the Grand Magisterium and by the President, and of the regulations emanating from the same Lieutenancies or Magistral Delegations and by the respective Councils, taking into account the legitimate traditions, customs and needs of the individual nations.”
(paragraph 4 of article 37)