The standard time line that I know shows no symptoms for the first 7-10years. Then symptoms start to show up in the next 5-7 years. Then the opportunistic illnesses like TB and PCP (pneumonia) start to show up. In third world countries, this time line may not apply.
When I was told I had AIDS in 1993, I had already finished the HIV time line and was living with AIDS. In 1994/5, I suffered TB. So I have had two AIDS defining illness.
When the CD4 counts are lower than 200, then a person is likely to get one or more of the 25-29 opportunistic illnesses.
All the best
Mson