Ahlmann took over at the summit last November, toppling Britain's Nick Skelton, and has remained untouchable during the eight months that have passed since.
Swiss rider Steve Guerdat, Kevin Staut of France and Dutchman Gerco Schröder have all threatened to dethrone Ahlmann at various points but none have been successful.
Ahlmann's latest win in the Hamburg Grand Prix on May 11 saw him maintain a healthy lead of 62 points over Staut and 125 over Schröder.
And there was little change to the remainder of the latest rankings.
American Beezie Madden moves up to fourth position after the points scored during the World Cup finals in Gothenburg.
Behind her lies Australian Edwina Tops-Alexander, who rises two places. Ludger Beerbaum is also on the up, from 12th to 17th, while Marcus Ehning drops from fifth to 10th.
One of the most impressive rises though is that of Daniel Deusser, who leaps 17 places from 44th to 27th following his eighth-placed finish in the Rome Grand Prix, Germany's second place in the Italian leg of the Nations Cup, victories in minor classes at Wiesbaden and Hamburg and a second place in the Hamburg GP.
- Sports & Recreation
- Kevin Staut
- Nick Skelton