Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Driver | Race 1 | Race 2 | Race 3 | Race 4 |
| --- | --- | --- | --- | --- |
| Craig Lowndes | 2 | 2 | 1 | 1 |
| Mark Skaife | 1 | 1 | 2 | 2 |
| Larry Perkins | DNF | 12 | 8 | 3 |
| Steven Richards | 9 | 7 | 6 | 4 |
| Russell Ingall | 5 | 4 | 3 | 5 |
| Jason Bright | 7 | DNF | 13 | 6 |
| Steve Ellery | 3 | 3 | 5 | 7 |
| Tony Longhurst | 6 | 6 | 14 | 8 |
| Rodney Forbes | DNF | 20 | 15 | 9 |
| Paul Romano | 31 | 14 | 12 | 10 |
| Terry Finnigan | 17 | DNF | 18 | 11 |
| Mark Larkham | 10 | 15 | 19 | 12 |
| Jason Bargwanna | DNF | 27 | DNS | 13 |
| Dugal McDougall | 23 | 23 | 17 | 14 |
| Wayne Wakefield | 22 | DNF | 21 | 15 |
| Trevor Ashby | 13 | 18 | 22 | 16 |
| Dean Lindstrom | 18 | 19 | 24 | 17 |
| David Parsons | 19 | DNF | 25 | 18 |
| Anthony Tratt | 21 | DNF | DNF | 19 |
| Rod Nash | 29 | 24 | 26 | 20 |
| Kevin Heffernan | DNF | 21 | DNF | 21 |
| Nathan Pretty | 24 | DNF | 27 | 22 |
| Mike Imrie | 28 | 26 | 29 | 23 |
| D'arcy Russell | 27 | 28 | DNS | 24 |
| Richard Mork | 30 | DNF | 30 | 25 |
| Steven Richards | 12 | 9 | DNS | 26 |
| Paul Weel | 15 | 17 | 20 | DNF |
| Simon Emerzidis | 25 | 22 | 23 | DNF |
| Mark Noske | DNF | 13 | 16 | DNF |
| Neil Crompton | 20 | 10 | 7 | DNF |
| Wayne Gardner | DNF | 11 | 9 | DNF |
| Cameron McLean | 11 | 29 | 32 | DNF |
| Mike Conway | 26 | 25 | 28 | DNF |
| Garth Tander | DSQ | 16 | 10 | DNF |
| Glenn Seton | DNF | DNF | 11 | DNF |
| John Faulkner | 14 | 8 | 31 | DNF |
| John Bowe | 4 | 5 | 4 | DNF |
| Dick Johnson | 16 | DNF | DNS | DNS |
| Paul Radisich | DNF | DNF | DNS | DNS |
| Todd Kelly | 8 | DNF | DNS | DNS |
Question:
What's the value for race 4 for driver kevin heffernan?
Answer:
21.0