So you work at Google but you're having trouble grasping simple mathematics? OK then. Let's break it down:

X is an over-represented group of Googlers threatening their diversity. Let's say it's males. Y is, let's say, women. Z is the total number of current Googlers.

In this case, 0.7Z = X and 0.3Z = Y. (70% men, 30% women).

Still with me?

If Google were to continue hiring X at the current rate (i.e., 70% of all candidates hired), then the diversity of Z will not change with respect to X and Y.

Therefore, in order to achieve the desired balance, Y must be >> X, be that through hiring (i.e., hire more Y than X) or firing (fire more X than Y). Rinse and repeat for other over- and under-represented groups at Google. I'm not sure why this concept is lost on you.

Maybe you didn't read my earlier post where I said that Google will hire as many qualified people as it can. There is no upper limit. Nobody is excluded because of quotas or whatever.

If Google has 100 X's and 10 Y's and hires 10 X's and 1 Y every year, the ratio of X's to Y's stays the same. If Google increases the number of Y's they hire each year to 2, the ratio of X's to Y's decreases. Not sure what's so hard to comprehend about this.