Note that the patent year is different from the natural year. In your case, for example,
The filing date is 20 1 1.8.20, so the first year of patent is 2011.8.20 ~ 2012.8.19.
The second year is 2012.8.20 ~ 2013.8.19.
In the third year, 2013.8.20 ~ 2014.8.19, ..., etc.
The general principle of patent payment is that you need to pay the annual fee for the next year in advance, so when you need to pay the fee for the fourth year, there is naturally no discount.
Note that preferential treatment refers to the patent year, not the natural year.
If you ask separately, it was applied on August, 2009 10 and authorized on March 30, 2065438. At that time, it was the patent fee paid that year, that is, the fourth annual fee, so there was no discount.
I don't know if the explanation is clear.