[AccessD] calculation query

Hello Group,

i need to calculate to forms of sympatry of some species.
The own-sympatry   (or accompanied species)       =  the percentages of how many coordinates are the same from species A; compared to B and compared to C
The foreign-sympatry    =  in which percentage of the coordinates where species B and species C are found, is also species A found 

The data that i have:
  TblSympatry ID Species Coordinate 
      1 A 11 
      2 A 13 
      3 A 14 
      4 A 11 
      5 A 14 
      6 B 11 
      7 B 15 
      8 B 15 
      9 B 16 
      10 B 17 
      11 C 11 
      12 C 14 
      13 C 14 
      14 C 16 
      15 C 18 



own-sympatry:
Species A is found in three different Coordinates. 
Species B is found in one of the three coordinates = 33,3%
Species C is found in two of the three coordinates = 66,6%

result: own-sympatry

own        percentage
A-B             33,3
A-C             66,6



foreign-sympatry    
Species B is found in four coordinates, Species A is found in one of these = 25%
Species C is found in four coordinates, Species A is found in two ot these = 50%

result: foreign-sympatry

foreign      percentage
B=A              25
C=A              50



A total of 25 species need to be compared which each to methods.

How can i do this in Access?

Thanks

Pedro