List the names of universities with a score less than 28% of the average score of all universities in 2015.
in 2015 refers to year = 2015; score less than 28% refers to score < MULTIPLY(avg(score), 0.28) where year = 2015; names of universities refers to university_name
SELECT T2.university_name FROM university_ranking_year AS T1 INNER JOIN university AS T2 ON T1.university_id = T2.id WHERE T1.year = 2015 AND T1.score * 100 < ( SELECT AVG(score) * 28 FROM university_ranking_year WHERE year = 2015 )