GRADE 9 SCIENCE

In July 2013, we sold an aggregate of $100.0 million principal amount of 4.25% convertible senior notes due on August 1, 2018, of which no amounts are currently outstanding, but $29.6 million were exchanged for new notes due on November 1, 2020 (the “3.25% 2020 Notes” and collectively with the 4.875% 2020 Notes, the “Notes”). ................
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