C,
In a paddock of high grass - Analogy:
GIIP90 is counting the rabbits you have actually seen
GIIP50 is the amount of rabbits in the field based on the number you have seen
GIIP10 is the highest number of rabbits the field could possibly hold
The first one will do it for me - then all you have to do is catch them - WHICH WE WILL!!!
MOHO