Calculate items in a table

I need to calculate the table items and display them in a certain field on my page.

Currently it looks like this:

<div class="pacientes">
        <div class="pacientes-header">
            <i class="fa fa-people-carry"></i>
                Pacientes pesquisados <span class="badge badge-pill badge-info align-top" id="countPacientes"></span>
            <button type="button" class="invitation-card-buttons btn btn-sm btn-outline-primary btn-lg check-all-list-items float-right">
                <i class="fa fa-check mr-1"></i> selecionar todos
            </button>
        </div>

        <div class="card-body">

            <div class="table-responsive">

                <table class="pacientes-table-plugin table table-hover table table-striped table-bordered">
                    <thead>
                    <tr class="text-center">
                        <th class="align-middle">#</th>
                        <th class="align-middle"><abbr title="Código">CÓD.</abbr></th>
                        <th class="align-middle">NOME</th>
                        <th class="align-middle">CPF</th>
                        <th class="align-middle">TELEFONE</th>
                        <th class="align-middle">ENDEREÇO</th>
                        <th class="align-middle">CEP</th>
                        <th class="align-middle">MÉDICO</th>
                    </tr>
                    </thead>
                    <tbody id="table-itens">
                        <tr class="loader">
                            <td colspan="100" style="display: none"></td>
                        </tr>
                        <tr>
                            <td colspan="100">
                                <div class="alert text-center text-muted">...</div>
                            </td>
                        </tr>
                        <tr>
                        </tr>
                    </tbody>
                </table>
            </div>

The id="countPacientes" is where the number of patients surveyed should appear. My Javascript event is as follows:

Pacientes.prototype = {
    $('.pacientes-table-plugin').on('change', function(){
        self.count_pac();
    });
}

And this is my current role:

count_pac : function(){
    const t = $('.pacientes-table-plugin tr').length;
    $('#countPacientes').text(t);
}

You are not returning any data type in my span .