When the maximum value is 100 the line of the part of the graph is of a smaller thickness.
[![line chart][1]][1]
The value cannot be more than 100.
yAxis: {
title: {
text: ''
},
tickAmount: 5,
labels: {
format: '{value}%',
style: {
color: 'var(--el-text-color-primary)'
}
},
min: 0,
max: 100
}```
[1]: https://i.sstatic.net/pBvTc3mf.png