Basicity comparison between pyridine amines and other compounds

[![1: pyridin‐4‐amine; 2: pyridin‐3‐amine; 3: aniline; 4: 1,4,5,6‐tetrahydropyrimidine](https://i.stack.imgur.com/4kQz0.png)](https://i.stack.imgur.com/4kQz0.png)


In cases **1**, **2**, **3**, the compounds will resonate, thus giving them more stability. 


Firstly, **I want to know whether nitrogen has a +M effect**? (due to it having a lone pair of electrons?)


In case **1**, resonance occurs and the electron density above the $\ce{NH2}$ group is delocalised, even in the cases **2**, and **3**, this is true. But in **1** the $\ce{N}$ is at the *para*-position, while in **2** the $\ce{N}$ is at the *meta*-position. How would that affect the order?


It would help if someone could hint at the factors coming into play here.


Case **4** is non-resonating, so it would be the most basic, right? How do I arrange the rest in order?


