Kalashtar were originally formed when 67 adaran monks fused their being with quori spirits from Dal Quor. All descriptions of the race, as well as their naming convention suggests a 1:1 ratio of human:quori, ie. that in one kalashtar there is exactly one quori and one human.
Combining these two statements could lead one to believe that the number of kalashtar is limited by the number of quori that escaped Dal Quor at that time. Is this so? I see no mention of such a cap.
If there can be more than 67 kalashtar at a time, where do the quori come from? Do they also reproduce? Do new ones escape Dal Quor?