Among a number of devices Apple Inc. is expected to unveil Thursday, its new iPads are feeling the heat. IPad sales have continued to fall over the past year, along with the rest of the tablet market, so the question surrounding Apple’s next pad is not just whether it can create a new hit but whether it can it finally convince legacy iPad users to upgrade.

This chart shows why Apple needs a hit:

iPad Device Share 2014 Apple's iPad 2 continues to have the largest share of users, according to mobile analytics and marketing firm Localytics Photo: Localytics

Of all the iPads on the market, the iPad 2 maintains the largest market share at 27 percent, with the iPad Mini (non-Retina) taking the second-largest share at 20 percent, according to mobile analytics and marketing firm, Localytics. Apple's current generation of products, the iPad Air and Retina iPad Mini, hold only 19 percent of the market.

A new iPad could be a compelling reason to upgrade, but the tablet hasn’t seen the kind of push that two-year upgrade cycles have had on users looking to upgrade their iPhones.

We’ll have to wait and see if Apple can turn its tablet around this year, or if it will eventually be consumed by another competitor: the iPhone 6 Plus.