your understanding is not accurate.

the income of the fund depends on the performance of the investment target of the fund, such as stocks.

Maybe your fund's current net value increased by 19.8% compared with the fund's net value in six months, but it fell six months ago and the fund experienced a decline, so the current net value increased less than that of a year ago.

It's May, and the net value of the fund five months ago increased by 11.7% compared with now, which indicates that there may be an increase of about 8% in December last year.

The return is 4% in two years, but 16% in one year, which means that the fund experienced a 12% decline.

this data only shows the comparison between the fund and its past performance.