PWM Output to 1 LED

// PWM Output to Pin 9  V1
// Steps between levels are equal
// But seems to be biased towards On

int level01 = 0;

void setup() {
  pinMode( 9, OUTPUT);
} //setup

void loop() {
  analogWrite( 9, level01);
  level01 = level01 + 1;
  if (level01 >= 256) {
    level01 = 0;
  }
  delay(10);
} //loop