I appreciate all the comments. I do agree that many VdlP pilgrims do not walk the whole way in one go, and I'm sure many do not bother with a Compostella, so I have no idea how these numbers compare to the actual total number of people who walk a portion of the VdlP in one year.
That being said, it seems that these characteristics would be consistent from year to year, so the fact that the number of Compostelas has been fairly flat for these last few years is significant.
I will also add a bit more data here. The Zamora albergue is VERY popular among pilgrims along this route, with most pilgrims on this segment, north of Salamanca, stopping there. The capacity is about 30 pilgrims per night, and there are only two months a year in which the albergue even averages 20 pilgrims/night. They are April and May (April = 18/day, and May = 22/day in 2017). In fact, for the busiest 6 months of 2017, the albergue had only about 2500 pilgrims (an average of only 14/day).
This low number of pilgrims midway through the VdlP is totally expected when compared to the number of Compostelas, because the numbers of pilgrims after Ourense increases dramatically due to it being the equivalent of Sarria on the
Camino Frances. Gotta love those 100km-ers!
If Momonne found full albergues on this route, it was because there is a spring rush, which roughly corresponds with leaving Seville from about March 20th to April 30th. If this 6 week time frame is avoided, it would be very unusual to find a full albergue on the VdlP. I left Seville on March 1, 2017 and was in albergues with only one or two other folks on several nights. This paragraph is my one-time caution to all of you planning to be on the VdlP this spring. There are not nearly as many pilgrims as the Frances or Portuguese, but there are also not nearly as many beds!
Buen Camino to all!