How to add % symbols

I have started with a project to control some functions in my Trailer.
Now everything works fine.

Trailer Project

I wonder how to add "°" and "%" ?

 SIM900.println("AT + CMGS = \"+46123456789\"");                 // recipient's mobile number, in international format
  delay(100);
  SIM900.println("Indoor temp:");                                 // message to send                         
  SIM900.println(t);  
  SIM900.println("Indoor humidity:"); 
  SIM900.println(h);

I like to send:
Indoor temp: 21.00°
Indoor humidity: 44.00%

Any help will be greatly appreciated !

I was hoping someone responded, because I don't believe those characters aren't in the permitted TEXT mode character set.
You could send the messages using PDU mode, which is a bit more complex, or simply add the symbols in your server side HTML.

Tout simplement :

SIM900.println("Indoor temp:"); // message to send
SIM900.print(t);
SIM900.println("°");
SIM900.println("Indoor humidity:");
SIM900.print(h);
SIM900.println("%");

33bert51...
Try it. Unless the default ETSI character set is different in French..?