IK: Your average credit amount on installment accounts is too low.
An installment account is one with a fixed monthly payment for the life of the loan. Auto loans and student loans are common examples of installment loans. The average credit amount on the installment accounts in your credit file is low, which is an indicator of higher risk.
Use your existing credit responsibly and make your payments on time. Your credit score will benefit as you make payments on time and manage the accounts in a responsible fashion. Manage your credit wisely by planning ahead for your credit needs so you can avoid applying for more credit than you need.