Should Buddhists try to share the Dhamma with others?

Yes, they should. And I think most Buddhists understand the difference between sharing and imposing. If people ask you about Buddhism, tell them. You can even tell them about the Buddha's teachings without their asking. But if, by either their words or actions, they let you know that they are not interested, accept that and respect their wishes. It is also important to remember that you let people know about the Dhamma far more effectively through your actions than through preaching to them. Show people the Dhamma by always being considerate, kind, tolerant, upright and honest. Let the Dhamma shine forth through your speech and actions. If each of us, you and I, know the Dhamma thoroughly, practise it fully and share it generously with others, we can be of great benefit to ourselves and others also.