You are now a sqlite data analyst, and you are given a database schema as follows:

    【Schema】
    【DB_ID】 formula_1
【Schema】
# Table: drivers
[
(driverId:INTEGER, Primary Key, Examples: [452, 625, 103]),
(driverRef:TEXT, Examples: [hamilton, heidfeld, rosberg]),
(number:INTEGER, Examples: [44, 6, 14]),
(code:TEXT, Examples: [HAM, HEI, ROS]),
(forename:TEXT, Examples: [Lewis, Nick, Nico]),
(surname:TEXT, Examples: [Hamilton, Heidfeld, Rosberg]),
(dob:DATE, Examples: [1985-01-07]),
(nationality:TEXT, Examples: [British, German, Spanish]),
(url:TEXT)
]
# Table: seasons
[
(year:INTEGER, Primary Key, Examples: [1950, 1951, 1952]),
(url:TEXT)
]
# Table: lapTimes
[
(raceId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(driverId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(lap:INTEGER, Primary Key, Examples: [1, 2, 3]),
(position:INTEGER, Examples: [13, 12, 11]),
(time:TEXT, Examples: [1:49.088, 1:33.740, 1:31.600]),
(milliseconds:INTEGER, Examples: [109088, 93740, 91600])
]
# Table: status
[
(statusId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(status:TEXT, Examples: [Finished, Disqualified, Accident])
]
# Table: constructors
[
(constructorId:INTEGER, Primary Key, Examples: [147, 39, 54]),
(constructorRef:TEXT, Examples: [mclaren, bmw_sauber, williams]),
(name:TEXT, Examples: [AFM, AGS, ATS]),
(nationality:TEXT, Examples: [British, German, French]),
(url:TEXT)
]
# Table: pitStops
[
(raceId:INTEGER, Primary Key, Examples: [841, 842, 843]),
(driverId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(stop:INTEGER, Primary Key, Examples: [1, 2, 3]),
(lap:INTEGER, Examples: [16, 36, 15]),
(time:TEXT, Examples: [17:28:24, 17:59:29, 17:27:41]),
(duration:TEXT, Examples: [23.227, 23.199, 22.994]),
(milliseconds:INTEGER, Examples: [23227, 23199, 22994])
]
# Table: qualifying
[
(qualifyId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(raceId:INTEGER, Examples: [18, 19, 20]),
(driverId:INTEGER, Examples: [1, 9, 5]),
(constructorId:INTEGER, Examples: [1, 2, 6]),
(number:INTEGER, Examples: [22, 4, 23]),
(position:INTEGER, Examples: [1, 2, 3]),
(q1:TEXT, Examples: [1:26.572, 1:26.103, 1:25.664]),
(q2:TEXT, Examples: [1:25.187, 1:25.315, 1:25.452]),
(q3:TEXT, Examples: [1:26.714, 1:26.869, 1:27.079])
]
# Table: races
[
(raceId:INTEGER, Primary Key, Examples: [837, 833, 838]),
(year:INTEGER, Examples: [2009, 2008, 2007]),
(round:INTEGER, Examples: [1, 2, 3]),
(circuitId:INTEGER, Examples: [1, 2, 17]),
(name:TEXT, Examples: [Australian Grand Prix]),
(date:DATE, Examples: [2009-03-29]),
(time:TEXT, Examples: [06:00:00, 09:00:00, 07:00:00]),
(url:TEXT)
]
# Table: results
[
(resultId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(raceId:INTEGER, Examples: [18, 19, 20]),
(driverId:INTEGER, Examples: [1, 2, 3]),
(constructorId:INTEGER, Examples: [1, 2, 3]),
(number:INTEGER, Examples: [22, 3, 7]),
(grid:INTEGER, Examples: [1, 5, 7]),
(position:INTEGER, Examples: [1, 2, 3]),
(positionText:TEXT, Examples: [1, 2, 3]),
(positionOrder:INTEGER, Examples: [1, 2, 3]),
(points:REAL, Examples: [10.0, 8.0, 6.0]),
(laps:INTEGER, Examples: [58, 57, 55]),
(time:TEXT, Examples: [1:34:50.616, +5.478, +8.163]),
(milliseconds:INTEGER, Examples: [5690616, 5696094, 5698779]),
(fastestLap:INTEGER, Examples: [39, 41, 58]),
(rank:INTEGER, Examples: [2, 3, 5]),
(fastestLapTime:TEXT, Examples: [1:27.452, 1:27.739, 1:28.090]),
(fastestLapSpeed:TEXT, Examples: [218.300, 217.586, 216.719]),
(statusId:INTEGER, Examples: [1, 11, 5])
]
# Table: constructorStandings
[
(constructorStandingsId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(raceId:INTEGER, Examples: [18, 19, 20]),
(constructorId:INTEGER, Examples: [1, 2, 3]),
(points:REAL, Examples: [14.0, 8.0, 9.0]),
(position:INTEGER, Examples: [1, 3, 2]),
(positionText:TEXT, Examples: [1, 3, 2]),
(wins:INTEGER, Examples: [1, 0, 2])
]
# Table: driverStandings
[
(driverStandingsId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(raceId:INTEGER, Examples: [18, 19, 20]),
(driverId:INTEGER, Examples: [1, 2, 3]),
(points:REAL, Examples: [10.0, 8.0, 6.0]),
(position:INTEGER, Examples: [1, 2, 3]),
(positionText:TEXT, Examples: [1, 2, 3]),
(wins:INTEGER, Examples: [1, 0, 2])
]
# Table: circuits
[
(circuitId:INTEGER, Primary Key, Examples: [23, 61, 29]),
(circuitRef:TEXT, Examples: [sepang, bahrain, catalunya]),
(name:TEXT, Examples: [Sepang International Circuit]),
(location:TEXT, Examples: [Kuala Lumpur, Sakhir, Montmeló]),
(country:TEXT, Examples: [Malaysia, Bahrain, Spain]),
(lat:REAL, Examples: [2.76083, 26.0325, 41.57]),
(lng:REAL, Examples: [101.738, 50.5106, 2.26111]),
(alt:INTEGER),
(url:TEXT)
]
# Table: constructorResults
[
(constructorResultsId:INTEGER, Primary Key, Examples: [1, 2, 3]),
(raceId:INTEGER, Examples: [18, 19, 20]),
(constructorId:INTEGER, Examples: [1, 2, 3]),
(points:REAL, Examples: [14.0, 8.0, 9.0]),
(status:TEXT, Examples: [D])
]
【Foreign keys】
lapTimes.raceId=races.raceId
lapTimes.driverId=drivers.driverId
pitStops.raceId=races.raceId
pitStops.driverId=drivers.driverId
qualifying.raceId=races.raceId
qualifying.driverId=drivers.driverId
qualifying.constructorId=constructors.constructorId
races.year=seasons.year
races.circuitId=circuits.circuitId
results.raceId=races.raceId
results.driverId=drivers.driverId
results.constructorId=constructors.constructorId
results.statusId=status.statusId
constructorStandings.raceId=races.raceId
constructorStandings.constructorId=constructors.constructorId
driverStandings.raceId=races.raceId
driverStandings.driverId=drivers.driverId
constructorResults.raceId=races.raceId
constructorResults.constructorId=constructors.constructorId

    【Question】
    What was the average time in milliseconds Lewis Hamilton spent at a pit stop during Formula_1 races? average time in milliseconds spent at pit stop refers to AVG(milliseconds)

    【Evidence】
    average time in milliseconds spent at pit stop refers to AVG(milliseconds)

    Please read and understand the database schema carefully, and generate an executable SQL based on the user's question and evidence. 

SQL: SELECT AVG(milliseconds) FROM pitStops AS T1 INNER JOIN drivers AS T2 on T1.driverId = T2.driverId WHERE T2.forename = 'Lewis' AND T2.surname = 'Hamilton'