I'm afraid I must disagree kurige, for two reasons. The first is that they smack of false modesty, a way of insuring yourself against the social consequences of failure without actually taking care not to fail. The second is that the use of such terms don't really convey any new information, and require the use of the passive voice, which is bad style.

"Evidence indicates an increase in ice cream sales" really isn't good science writing, because the immediate question is "What evidence?". It's much better to say "ice cream sales have increased by 15%" and point to the relevant statistics.