Frequency/Pulse Measurement

Hi Guys!

It's a little later on in this project now and I went back to look at the anemometer readings I was getting and there are some one off readings where the wind speed suddenly just reads 0.00 mph then carries on reading the wind speed as usual.

Is it possible to modify the below code to get a rolling average of anemometer readings from the previous 10 readings?

const byte BUTTON = 2;
float elapsed, diff, start;
float windspeed;

// Begin Setup-----------------------------------------------------------------
void setup ()
{
  Serial.begin(9600);
  digitalWrite (BUTTON, HIGH);                   // internal pull-up resistor
  attachInterrupt (0, pinChange, RISING);        // attach interrupt handler
  start = millis();
  Serial.println("WindSpd");
} 

// Interrupt Process for Windspeed Measurement---------------------------------
void pinChange ()
{
  elapsed=millis()-start;         //gets the full period (in ms) of rotation 
  windspeed=2.5/(elapsed/1000);   //gets freq from ms then * by 2.5 to get mph
  start=millis();                 //resets the counter
}  
// end of Interrupt Process----------------------------------------------------

// Main Loop-------------------------------------------------------------------
void loop ()
{  
//Begin Serial Printing
  Serial.print(windspeed);
  Serial.print(" ");
  Serial.println("mph");

//End Serial Printing

  delay(200);
}