## Quality formula for the article
**List of RPM number-one country singles of 1974** ^{en}

$$Quality=1/c∑↙{i=1}↖c nm_i-RS=1/6(7.99+0+0+21.43+0+0)$$

where:

- $nm_i$ is normalized quality metric $i$
- $c$ is the number of quality metrics
- $RS$ is the reducing score (if exists)

The results of the calculations may be slightly different because of rounded values of normalized metrics in formulas