Human Immunodeficiency Virus (HIV) is a viral pathogen that attacks the body's immune system. Table 1 shows information about new HIV diagnoses in a region over several years, split by age group.
| Year | Number of new HIV diagnoses (Age 15–24) | Number of new HIV diagnoses (Age 25 and over) |
|---|---|---|
| 2014 | 520 | 2150 |
| 2016 | 565 | 2310 |
| 2018 | 490 | 1980 |
| 2020 | 385 | 1620 |
| 2022 | 245 | 1150 |
State one way the Human Immunodeficiency Virus (HIV) can be transmitted from one person to another.
Describe the trends shown in Table 1 for new diagnoses of HIV in both age groups between 2014 and 2022.
Calculate the ratio of new HIV diagnoses in the 15–24 age group to new diagnoses in the 25 and over age group in 2022. Give your answer to 3 significant figures in the form N:1N : 1N:1.