output time difference at end of loop

bfps/_fluid_base.py

@@ -197,14 +197,13 @@ class _fluid_particle_base(_code):
                                   'time0 = time1;\n')
         self.main       += 'for (int max_iter = iteration+niter_todo; iteration < max_iter; iteration++)\n'
         self.main       += '{\n'
-        self.main       += output_time_difference
         self.main       += 'if (iteration % niter_stat == 0) do_stats();\n'
         if self.particle_species > 0:
             self.main       += 'if (iteration % niter_part == 0) do_particle_stats();\n'
             self.main   += self.particle_loop
         self.main       += self.fluid_loop
-        self.main       += '}\n'
         self.main       += output_time_difference
+        self.main       += '}\n'
         self.main       += 'do_stats();\n'
         self.main       += 'do_particle_stats();\n'
         if self.particle_species > 0: