Below is Data on Air Pollution in Des Moines over the past 20 years. 𝑡 represents years since 2003. (source: epa.gov/air-data)
t
Air Pollution in Des Moines (%)
0
37
1
29
2
40
3
29
4
38
5
37
6
29
7
33
8
32
9
36
10
29
11
22
12
19
13
16
14
20
15
22
16
17
17
16
18
22
19
13
Let 𝑃𝑡 be a function that models the level of air pollution in Des Moines 𝑡 years after 2003.
In 2020, there was a significant reduction in the number of drivers on the roads of Des Moines.
Based on this information, what is a reasonable domain restriction to put on 𝑃𝑡?