Table:
text: Athletics at the 2007 All-Africa Games
Medal table
Medal table
Rank_ Nation Gold Silver Bronze Total
1 Nigeria 9 8 7 24
2 South Africa 7 9 8 24
3 Tunisia 5 1 4 10
4 Botswana 5 0 0 5
5 Ethiopia 4 4 5 13
6 Kenya 3 6 3 12
7 Egypt 3 3 0 6
8 Sudan 3 0 1 4
9 Ghana 2 3 2 7
10 Algeria 1 3 6 10
11 Senegal 1 1 0 2
12 Eritrea 1 0 1 2
13= Mozambique 1 0 0 1
13= Uganda 1 0 0 1
15 Zimbabwe 0 1 2 3
16= Burkina Faso 0 1 1 2

text: Athletics at the 2007 All-Africa Games
Medal table
Medal table
Rank_ Nation Gold Silver Bronze Total
16= Namibia 0 1 1 2
18= Cameroon 0 1 0 1
18= Madagascar 0 1 0 1
18= Mauritius 0 1 0 1
18= Seychelles 0 1 0 1
18= Tanzania 0 1 0 1
23 Ivory Coast 0 0 2 2
24= Benin 0 0 1 1
24= Guinea 0 0 1 1
24= Mali 0 0 1 1
24= Togo 0 0 1 1
Total Total 46 46 47 139

Question: What is the greatest silver with less than 0 gold for track and field at the 2007 All-Africa Games?