[{"account_id":11,"event":ISODate("2021-05-03T10:33:18.220Z")},{"account_id":11,"event":ISODate("2021-05-03T10:33:19.220Z")},{"account_id":11,"event":null},{"account_id":99,"event":ISODate("2021-05-03T10:33:20.220Z")},{"account_id":99,"event":null}]

db.collection.aggregate([{$match:{account_id:11}},{$facet:{total:[{$group:{_id:null,count:{$sum:1}}}],with_event:[{$match:{event:{$type:9}}},{$group:{_id:null,count:{$sum:1}}}]}},{$project:{total:{$arrayElemAt:["$total.count",0]},with_event:{$arrayElemAt:["$with_event.count",0]}}}])