avoid NPE if grades haven't been curved yet
avoid NPE if grades haven't been curved yet

blerner/bottlenose,CodeGrade/bottlenose,CodeGrade/bottlenose,CodeGrade/bottlenose,CodeGrade/bottlenose,blerner/bottlenose,blerner/bottlenose,CodeGrade/bottlenose,CodeGrade/bottlenose,blerner/bottlenose,blerner/bottlenose,blerner/bottlenose,blerner/bottlenose,CodeGrade/bottlenose