Which major has between 2 and 30 number of students? List major and the number of students.
return major  ;return students of #1 ;return number of  #2 for each #1 ;return #1 where #3 is  at least 2 ;return #1 where #3 is  at most 30 ;return #1 of both #4 and #5 ;return students of #6 ;return number of  #7 ;return #7 ,  #8
['select', 'project', 'group', 'comparative', 'comparative', 'intersection', 'project', 'aggregate', 'union']