I have been trying to collect accurate ball in play time data in rugby union since the late 1970s.
Their lapsed-time analysis of the thirty-two games played at the 1995 Rugby World Cup provided these time data:
The ball out of play time comprised:
Ball in play time in individual games ranged from a high of 31 min 56s (Australia v Canada) to a low of 21 min 50 s (France v Tonga).
The Final between South Africa and New Zealand had a total game time of 82 min 02 s and a ball in play time of 26 min 43 s.