Table:
text: 1986–87 Northern Premier League
Final table
Final table
Position_ Team Played Drawn Lost Goals_For Goals_Against Goal_Difference Points_1
1 Macclesfield Town 42 10 6 80 47 +33 88
2 Bangor City 42 12 5 74 35 +39 87
3 Caernarfon Town 42 16 6 67 40 +37 76
4 Marine 42 10 11 70 43 +27 73
5 South Liverpool 42 10 11 58 40 +18 73
6 Morecambe 42 12 10 66 49 +17 72
7 Matlock Town 42 10 12 81 67 +14 70
8 Southport 42 11 12 67 49 +18 68
9 Chorley 42 12 14 58 59 −1 60
10 Mossley 42 12 15 57 52 +5 57

Question: What is the goal difference for Chorley team in Northern Premier League 1986-87?