With some Excel magic, I have come up with this tally! These are the tallies of Pokemon in the Kalos Pokedex, grouped by their region of origin:

**Kanto:** 111 (24.2%)

**Johto:** 63 (13.7%)

**Hoenn:** 79 (17.2%)

**Sinnoh:** 52 (11.3%)

**Unova:** 80 (17.5%)

**Kalos:** 72 (15.7%)

**Total:** 457 (100%)

And this total number is verified by Bulbapedia (in the Trivia section), so Excel counted everything correctly.

Your observation proves to be true: apart from the Kanto, Kalos is mostly habited by Hoenn- and Unova-based Pokemon.

Other random statistics; the Kalos Pokedex consists of...

73.5% of all Kanto Pokemon (111/151).

42% of all Johto Pokemon (63/150).

58.5% of all Hoenn Pokemon (79/135).

48.5% of all Sinnoh Pokemon (52/107).

51.2% of all Unova Pokemon (80/156).

100% of all Kalos Pokemon (surprisingly, 72/72).

Hope I helped. :)

Source: Above link