I am trying to get stats on how many docs were created per period

[
  {
    $bucket: {
      groupBy: "$createdAt",
      boundaries: [
        ISODate("2024-06-01"),
        ISODate("2024-06-30"),
        ISODate("2024-07-01"),
        ISODate("2024-08-30")
      ],
      default: null,
      output: {
        count: {
          $sum: 1
        },
        arr: {
          $push: {
            createdAt: "$createdAt"
          }
        }
      }
    }
  },
  {
    $match: {
      _id: {
        $ne: null // exclude the default
      }
    }
  },
]

But I want to know in each period for example

ISODate("2024-06-01"),
ISODate("2024-06-30"),

between those dates (and for each period in boundaries) what are the minimum, maximum, and avg inserted docs per day…
any suggestion?