How many shipments did Holger Nohr transport to North Las Vegas overall?
"North Las Vegas" is the city_name
SELECT COUNT(*) FROM driver AS T1 INNER JOIN shipment AS T2 ON T1.driver_id = T2.driver_id INNER JOIN city AS T3 ON T3.city_id = T2.city_id WHERE T1.first_name = 'Holger' AND T1.last_name = 'Nohr' AND T3.city_name = 'North Las Vegas'