Possible Clues:

• Seldom
• Rarely
• Infrequently
• 'This isn't usually 10's, it seems (3,5)'
• 'Not X's, but seldom (3,5)'
• Once in a blue moon
• 'Seems it isn't X's but seldom is (3,5)'
• This isn't either X's or frequently
• Perhaps 22 across X's, but seldom
• Seldom this isn't X's, it seems