There are 4 main reasons in the survey for showing the main reasons for teenagers in one African country usingwhy African teenagers used their phones between 2016 and 2019:

1. Social networksing

1. The rates of them are decreasing from up and down in every chart between 2016 and 2019.

Which areUse increased from 50% to 56%.

3.. The rate of Email is decreasinged in the four years.

Which areUse decreased from 25% to 19%.

4. The rate of Digital camera is accumulatinguse grew in the four years except year 2017.

Which areUse increased from 15% to 20%.

5. The rate of Phone calls is decreasinged in the four years except year 2017.,

Wwhich arewas from 10% to 5%.

1. All the dates of the chart are changing stable in these yearsstable, except year 2017.

2. People in African are getting more and more into social networks, and digital camera use on their phones between 2016 and 2019 by phones.

3. People in African are getting less and less into email and phone calls between 2016 and 2019 by phones.

There are 4 reasons in the survey for showing the main reasonsfour main reasons, as stated in a survey conducted between 2016 and 2019, for teenagers in one African country usingto use their phones between 2016 and 2019:: to access social networks, to send emails, as digital cameras, and for phone calls.

Numbers smaller than ten should be written out in academic writing. Your numbered list can be added to this sentence by using a colon ( : ). Your list would be stronger by adding a matching verb to each reason, but it's not always necessary. You could just write your list as "social networks, emails, digital cameras, and phone calls" and it would still be fine.

Another way to write this sentence would be: "In the survey conducted between 2016 and 2019, the four main reasons teenagers in one African country use their phones are social networks, emails, digital cameras, and phone calls."

1. The rates of themse reasons are deincreasing from up and downand decreasing in every chart (between 2016 and 2019).

Since your audience knows what the dates are from the previous section, you don't necessarily need to add them here.

2. The rate of Saccessing social networks is accumulatinghas increased in the four years except year 2017.

This sentence works better with adding a verb after "the rate of". "Accessing" was the first one to come to mind, but you could also use something like "logging onto" or "using"

Which areOverall, it has increased from 50% to 56%.

3.. The rate of Eemail isusage has been decreasing inover the four years, from 25% to 19%.

Similar reason as what I said before. I also combined your next sentence with this one.

4. The rate of Digital camera is accumulatingusing phones as digital cameras has risen in the four years except the year 2017, from 15% to 20%.

Again, needs a verb here. This one is a little different than the others because it's a comparison, using something in the place of another. Also, I combined your next sentence and this sentence.

5. The rate of Phone calls ihas decreasinged in the four years except the year 2017, from 10% to 5%.

Consclusion:

1. All the datesinformation ofn the chart areis consistently changing stable in these years except the year 2017.

2. People in this African country are getting more and more into social networks, and digital camera between 2016 and 2019 byphotography by using their phones.

3. People in African areare also getting less and less into email and phone calls between 2016 and 2019 by phones.

I edited out the parts that were redundant.