elements = runif(1000)

effectifs = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
keys = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0)

for (i in 0:9) {
  borne_min = i/ 10
  borne_max = (i + 1) / 10
  
  for (e in elements) {
    if (e >= borne_min && e <= borne_max) {
      effectifs[i + 1] = effectifs[i + 1] + 1
    }
  }
  
  keys[i + 1] = i + 0.5
}

df = data.frame(keys, effectifs)

print(df)