minor javadoc changes

src/main/java/com/dynatrace/dynahist/Histogram.java

@@ -136,7 +136,7 @@ default long getUnderflowCount() {
   boolean isEmpty();
 
   /**
-   * Returns an estimation for the value with given (0-based) rank.
+   * Returns an estimation for the value with given (zero-based) rank.
    *
    * <p>The values within a histogram bin are assumed to be uniformly distributed. If the bin count
    * is N, the interval spanned by the bin is divided into N subintervals. The values are
@@ -156,7 +156,7 @@ default long getUnderflowCount() {
    * #getPreprocessedCopy()} into a @link {@link PreprocessedHistogram} first (which is an O(N)
    * operation), whose implementation has a worst case complexity of O(log N).
    *
-   * @param rank the 0-based rank, must be nonnegative and less than {@link #getTotalCount()}
+   * @param rank the zero-based rank, must be nonnegative and less than {@link #getTotalCount()}
    * @return an approximation for the value with given rank
    */
   double getValueEstimate(long rank);
@@ -199,7 +199,7 @@ default long getUnderflowCount() {
    * <p>Preprocessing is recommended, if many calls of {@link #getBinByRank(long)} or {@link
    * #getValueEstimate(long)} are expected.
    *
-   * @return an immutable copy of this histogram
+   * @return an immutable pre-processed copy of this histogram
    */
   Histogram getPreprocessedCopy();