Table 1 Types of coupled development.

Dysfunctional decline

(0 ≤ R < 0.5)

0 ≤ R < 0.2

Severe dysfunction

0.2 ≤ R < 0.3

Serious dysfunction

0.3 ≤ R < 0.4

Moderate dysfunction

0.4 ≤ R < 0.5

Mild dysfunction

Coordinated development

(0.5 ≤ R ≤ 1)

0.5 ≤ R < 0.6

Basic coordination

0.6 ≤ R < 0.7

Intermediate coordination

0.7 ≤ R < 0.8

Good coordination

0.8 ≤ R ≤ 1

High-quality coordination