A quote from the one website I was able to get to:
"In this case, we’ve interpolated across some of the missing data areas to minimize the visual distraction that results from the areas of missing data jumping around from map to map over time."
interpolation and missing data mean fake numbers.  You have a theory that you want to be true  and are manipulating data to support it.  Also, carbon 14 is NOT the most reliable of testing methods, despite what you might have been taught in your liberal indoctrination center.  It has given many a false reading.