|Pos|No|Driver|Constructor|Laps|Time/Retired|Grid|Points|
|---|---|---|---|---|---|---|---|
|1|15|Sebastian Vettel|Red Bull-Renault|56|1:57:43.485|1|10|
|2|14|Mark Webber|Red Bull-Renault|56|+10.970|3|8|
|3|22|Jenson Button|Brawn-Mercedes|56|+44.975|5|6|
|4|23|Rubens Barrichello|Brawn-Mercedes|56|+1:03.704|4|5|
|5|2‡|Heikki Kovalainen|McLaren-Mercedes|56|+1:05.102|12|4|
|6|1‡|Lewis Hamilton|McLaren-Mercedes|56|+1:11.866|9|3|
|7|10|Timo Glock|Toyota|56|+1:14.476|19|2|
|8|12|Sébastien Buemi|Toro Rosso-Ferrari|56|+1:16.439|10|1|
|9|7|Fernando Alonso|Renault|56|+1:24.309|2||
|10|4|Kimi Räikkönen|Ferrari|56|+1:31.750|8||
|11|11|Sébastien Bourdais|Toro Rosso-Ferrari|56|+1:34.156|15||
|12|6‡|Nick Heidfeld|BMW Sauber|56|+1:35.834|11||
|13|5|Robert Kubica|BMW Sauber|56|+1:46.853|17||
|14|21|Giancarlo Fisichella|Force India-Mercedes|55|+1 Lap|20||
|15|16|Nico Rosberg|Williams-Toyota|55|+1 Lap|7||
|16|8|Nelson Piquet, Jr.|Renault|54|+2 Laps|16||
|17|20|Adrian Sutil|Force India-Mercedes|50|Accident|18||
|Ret|17|Kazuki Nakajima|Williams-Toyota|43|Transmission|14||
|Ret|3|Felipe Massa|Ferrari|20|Electrical|13||
|Ret|9|Jarno Trulli|Toyota|18|Collision damage|6||

Question: what is the total number of drivers on the list?
Answer: 20