The given table shows the number of employees in three organisations during three years.
| Organisation | Year | ||
| 2015 | 2016 | 2017 | |
| L | 1421 | 1230 | 1652 |
| M | 1459 | 1825 | 1740 |
| N | 1620 | 1125 | 1235 |
What is the respective ratio between the total number of employees in organisations L and M together in 2015, and the total number of employees in organisations M and N together in 2017?