Agree with SSM
Part of the adjudication for the Judd/TOGS/Skinners last year considered the number of places available in GS and found that everyone who passed and wanted a place at GS got one before the start of the year (and that's in the overcrowded West Kent area). I suspect the figures you are looking at are the 'raw applications' and you need to adjust for the fact that everyone is given the opportunity to apply to up to four schools.
However the amount you have to struggle/fight to make that happen varies greatly depending on what part of Kent you are in. If you can let us know what area you live in I'm sure there will be plenty of freely given advice
on here from those who live nearby.