Progamação do Medidor de Distância

#include <HCSR04.h>

HCSR04 sonar (12,11);//initialisation class HCSR04 (trig pin , echo pin)
float distance = 0;
void setup(){
  Serial.begin(9600);
  
}

void loop(){
  distance = sonar.dist();
   //Serial.print( distance ); 
   //Serial.println ("cm");
   
   if (distance  >= 4 && distance <= 6){
   Serial.println ("resta 100% de papel higienico");
   }
   
   if (distance  >= 6.1 && distance <= 8) {
   Serial.println ("resta 75% de papel higienico");
   }
   if (distance  >= 8.1 && distance <= 10) {
   Serial.println ("resta 50% de papel higienico");
   }
   if (distance  >= 9.1 && distance <= 12) {
   Serial.println ("resta 25% de papel higienico");
   }
   if (distance  >= 12.1 && distance <= 14) {
   Serial.println ("resta 0% de papel higienico");
   }
   }