If you read Gaddis, he gives some good insight into the quantity of models ordered. In 1967 it was model 14 at 70 per month and models 1,18, and 15 around 35 to 55 each. By 1968 the 14 and 18 were both ordered at a rate of 30 to 60 per month. Models 1, 2 and 15 followed with monthly requests in the 15 to 30 range.

Obviously it varied but I think the point he was making was the shift away from "traditional" models i.e. 1 and 2 to the full tang variety as the war progressed.