Kinky (above) is correct. While TWO sellos per day are required in the final 100 Km, regardless of the Camino route you are on, it is also true, as a general statement, that, if all the rest of your sellos establish a line of march from a far distant point of origin, Porto, Sevilla, St. Jean Pied de Port, etc., they do tend to be more flexible.
This DOES NOT mean that you only need one sello per day in the final 100 km. It DOES mean that if you miss getting two sellos per day for a day or two, during your final 100 Km, they are unlikely to make a big deal of it.
The rule is there to try to deter the folks who only walk 100 km and obtain too few sellos. Walking a short distance and only having a few sellos, suggests (only suggests) fraud. This is just a fact, over time.
This is also why hyper-distance folks, who seek to do a Camino in an insanely short amount of time, draw attention to themselves. It is why they need to bend over backwards to get many, redundant sellos and take multiple, location & time stamped stamped photos on their smartphones daily to establish their rapid progress and line of march.
If you re a hyper-distance or even a short-distance pilgrim, it also wise to pay attention to unique architectural features, cafes, restaurants, and statues in the villages as you pass rapidly through them. The staff at the counter may ask you about location x, or cafe y, knowing that every passing pilgrim is aware of them. During the summer months, this 'cat & mouse' game is played out daily as fraudulent Compostela seekers attempt to 'put one over.' Avoid this game. Pay attention as you are on Camino. Observe your surroundings.
Hope this helps.