WSP | January 2013 (x) | Before 2004 (y) | Difference (x − y) |
CHEMOSIT | 7.6 | 7.2 | 0.4 |
KIWASCO | 6.3 | 5.5 | 0.8 |
MIKUTRA | 5.3 | 5.6 | −0.3 |
SNWSCO | 5.7 | 6.7 | −1 |
MOGOMBET | 5.1 | 5.3 | −0.2 |
BOYA | 3.6 | 3.65 | −0.05 |
NYASARE | 5.2 | 6.6 | −1.4 |
OVERALL MEAN | 5.9 | 6.1 | −0.2 |