The confidence interval (95%) is visualised with a transparent area.

Reading example: 38.6% of the 2017 population belonged to the middle income group in the entire observation period 2017–2020 (i.e. in all four years). 43.5% of the population belonged to the middle income group in all of the first three years of observation (2017-2019).
Only persons who participated in SILC from 2017 to 2020 and responded in all four survey years are considered.