The calculation formula of defective rate is: defective rate = number of defective products/total number of products × 100%. As the name implies, the defective rate refers to the proportion of defective products in the product. Generally speaking, in life and production, to understand the overall quality and efficiency of production, it is necessary to count the yield of products or the yield of products. In financial loans, the non-performing loan ratio often refers to the proportion of non-performing loans of financial institutions to the total loan balance. Loans are generally divided into five types according to the risk level: normal, concerned, secondary, suspicious and loss, among which secondary, suspicious and loss are non-performing loans.