import collections


def _counts(data):
    """Return a count collection with the highest frequency.

    >>> _counts([1, 1, 2, 3, 3, 3, 3, 4])
    [(3, 4)]

    >>> _counts([2.75, 1.75, 1.25, 0.25, 0.5, 1.25, 3.5])
    [(1.25, 2)]
    """
    table = collections.Counter(iter(data)).most_common()
    if not table:
        return table
    maxfreq = table[0][1]
    for i in range(1, len(table)):
        if table[i][1] != maxfreq:
            table = table[:i]
            break
    return table