For how many patients has each physician administered treatments? Provide the last name of the physician and number of patients. Make sure you include physicians who haven't administered any. 21. Which physicians are doing more than the average in terms of number of treatments administered? Show the physician last name and the number of treatments (over the average, of course) that they have administered. 22. Write the code that will change all the duration in the appointment table from minutes (which they are now) to hours. More Challenging Queries 23. What are the names and uses of drugs that have been administered during appointments lasting more than 70 minutes? 24. Who are the patients (include patient IDs and last names) over 50 years old who have had appointments lasting less than 100 minutes? 25. List the last names and salaries of physicians who have administered appointments lasting less than 40 minutes. 26. Provide details (all columns/fields) for the appointment(s) that lasted the longest. 27. How many appointments has each physician administered? Provide the physician last name and number of appointments. 28. Which physicians are doing more than the average in terms of number of appointments administered? Show the physician last name and the number of appointments (over the average, of course) that they have administered.