Why Is My VP$IP So Low?

[Spt2527]

After close to 3900 hands (which I know is still a very small sample size), my VP$IP is only 14.25 on .25/.5 limit tables. I'm wondering what hands I'm not playing that I should be playing. I use a starting hands chart that a 2+2er provided me that is from Sklanksy I believe, and looking at PT, my VP$IP does increase as my position gets closer to the button. My PFR % is only 6.45, though I feel as though I'm more aggressive than that. What hands do you guys think I should add to my arsenal of playable/raising hands? My raisers are AA-99, AK-AJ(AJ when in position), AKs-ATs(ATs anywhere but EP), KQs-KJs(KJs when in position), KQ, KJ in late positon, and a few others when I think I can steal. I also play things like JT-T9s when I can get in for one bet. Any input is appreciated.