Arduino mini : No correct output

this week i've received my arduino mini
i 've made a simple sketch

void setup()
{
  // put your setup code here, to run once:
  Serial.begin(19200);
}
int number =0;
void loop()
{
  Serial.print("nr is");
  Serial.println(number);
  delay(500);
  number++;
  // put your main code here, to run repeatedly:
  
}

but the output in a serial monitor is.

§
b§Ä
b§Ä¥b§Ä¥b§Ä
bÍÄ
bçÄ¥b§Ä¥b§ÄÅbÏÄEb§Ä
Dó§Ä
DóÏÄ
Eó§Ä
Eó§
Dó§Ä
Dó

tested with 2 different arduinos mini

That looks like you are not setting the Serial Monitor baud rate correctly.

Which minis are you using? 3.3V 8 MHz or 5.0V 16 MHz? If they are the 3.3V models, you'll need to set the baud rate on the Serial Monitor to half or double that of the Arduino, since it expects to be communicating with a 16 MHz model.

Double the baudrate did it . . . thank you