mongodb type setting after csv import

gistfile1.txt

var cursor = db.zomg.find()
while (cursor.hasNext()) {
  var doc = cursor.next();
  db.zomg.update(
    {_id : doc._id}, 
    {$set : {
       dropoff_datetime: new Date(doc.dropoff_dateime) ,
       dropoff_latitude: new Number(doc.dropoff_latitude) ,
       dropoff_longitude: new Number(doc.dropoff_longitude) ,
       fare_amount: new Number(doc.fare_amount) ,
       hack_license: new String(doc.hack_license) ,
       medallion: new String(doc.medallion) ,
       mta_tax: new Number(doc.mta_tax) ,
       passenger_count: new Number(doc.passenger_count) ,
       payment_type: new Number(doc.payment_type) ,
       pickup_datetime: new Date(doc.pickup_datetime) ,
       pickup_latitude: new Number(doc.pickup_latitude) ,
       pickup_longitude: new Number(doc.pickup_longitude) ,
       rate_code: new Number(doc.rate_code) ,
       surcharge: new Number(doc.surchage) ,
       tip_amount: new Number(doc.tip_amount) ,
       tolls_amount: new Number(doc.tolls_amount) ,
       total_amount: new Number(doc.total_amount) ,
       trip_distance: new Number(doc.trip_distance) ,
       trip_time_in_secs: new Number(doc.trip_time_in_secs),
       vendor_id: new String(doc.vendor_id) 
    }
    })
}