Get MailChimp Subscribers (Member Count) in Google Sheets

function mailchimpListInfo() {
  var API_KEY = 'XXXXX-us1'; // MailChimp API Key
  var LIST_ID = 'XXXXX'; // List ID

  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheetByName("MemberData");

  var dc = API_KEY.split('-')[1];
  var api = 'https://'+ dc +'.api.mailchimp.com/3.0';

  var memberList = '/lists/'+LIST_ID;
  var options = {"headers": {"authorization": 'apikey '+API_KEY}};
  var apiCall = function(endpoint){
    apiResponseMembers = UrlFetchApp.fetch(api+endpoint,options);
    var json = JSON.parse(apiResponseMembers);
    return json
  }

  var members = apiCall(memberList);
  if (members) {
    var listInfos = {
      "Date": new Date(), /* Now */
      "Subscribers": members.stats.member_count,
      "Unsubscribe Count": members.stats.unsubscribe_count,
      "Cleaned Count": members.stats.cleaned_count,
      "Member Count Since Send": members.stats.member_count_since_send,
      "Unsubscribe Count Since Send": members.stats.unsubscribe_count_since_send,
      "Cleaned Count Since Send": members.stats.cleaned_count_since_send,
      "Campaign Count": members.stats.campaign_count,
      "Campaign Last Sent": members.stats.campaign_last_sent,
      "Merge Var Count": members.stats.merge_field_count,
      "Average Subscription Rate": members.stats.avg_sub_rate,
      "Average Unsubscription Rate": members.stats.avg_unsub_rate,
      "Average Target Subscription Rate": members.stats.target_sub_rat,
      "Open Rate": members.stats.open_rate,
      "Click Rate": members.stats.click_rate,
      "Date of Last List Subscribe": members.stats.last_sub_date,
      "Date of Last List Unsubscribe": members.stats.last_unsub_date,
      "List Rating": members.list_rating
    };
    var listInfosKeys   = Object.keys(listInfos);
    var listInfosValues = Object.keys(listInfos).map(function(key){return listInfos[key]});

    // Append MailChimp data to Spreadsheet
    if(sheet.getLastRow() === 0) {
      sheet.appendRow(listInfosKeys);
    }
    sheet.appendRow(listInfosValues);
  }
}