SANTIAGO, Chile (AP) — The approval ratings of Chilean President Michelle Bachelet have dropped to a new low, according to a new poll released Wednesday.

The monthly survey by pollster Gfk Adimark says Bachelet's overall approval slipped by 3 percentage points to 42 percent. That's the lowest rating in the poll since her return to the presidency in March.

The pollster says the reasons for the drop include frustration over repeated failures in November in Santiago's subway system that affected thousands of users. It also includes rising questions by the opposition and teachers over the government's plan for an education overhaul.

Bachelet says she's addressing the concerns of millions of students who have staged protests since 2011 demanding deep changes in an educational system that fails them with poor-quality public schools and expensive private universities.