The rate of setting new daily record highs or lows is related to natural variability (e.g., temperature oscillations), long-term trends, and how many years you analyze (i.e., the period of record). Absent a trend, it is true that relatively stable and well-behaved natural variability would, on average, lead to records being set at a rate near 1/N, where N is the number of years in your period of record. So, for a 100-year period of record, one would expect ~1% of readings to be record highs and ~1% of readings to be record lows on average. So, in theory the rate of setting records would go down over time (as N gets bigger). If there is a meaningful trend, one would expect, on average, a greater frequency of cold records versus warm records when the long-term temperature trend is downward, and a greater frequency of warm records versus cold records when the long-term temperature trend is upward. In this analysis, we are focusing on the relative frequencies of warm versus cold records, which is essentially a characterization of climate change (i.e., upward trend) impacts. If we weren't observing a meaningful trend, it would make sense for an increasing rate of setting records (either warm or cold) to be associated with more energetic natural variability. However, that is not the scenario we are experiencing, and at the annual global temperature scales, the natural variability about the long-term trend since 1975 has been remarkably low versus pre-1975 periods.