What is NRR in statistics?
In population ecology and demography, the net reproduction rate, R0, is the average number of offspring (often specifically daughters) that would be born to a female if she passed through her lifetime conforming to the age-specific fertility and mortality rates of a given year.
The net reproduction rate in the presence of migration, call it NRR*, indicates how many daughters would be born, on average, to a cohort of female babies who pass through life and are subject at each age to observed rates of fertility, mortality, and migration (Preston and Wang, 2007; Hisashi, 2009).
GRR is also commonly referred to as Gross Renewal Rate. Net Revenue Retention (NRR) Rate, also known as Net Dollar Retention (NDR), is the percentage of recurring revenue retained from existing customers in a defined time period, including expansion revenue, downgrades, and cancels.
The net reproduction rate (NRR) represents the mean number of surviving daughters of a woman, based on prevailing rates for age-specific fertility and mortality.
It is determined by calculating the average number of surviving daughters born to the women in that population during their reproductive years. An NRR of 1 indicates that each woman in the population has one surviving daughter during her lifetime.
- NRR = ((MRR at Start of Month + Expansion MRR) – (Churn MRR + Contraction MRR)) ÷ (MRR Start of Month) × 100% ...
- GRR = ((MRR at Start of Month) – (Churn MRR + Contraction MRR)) ÷ (MRR Start of Month) × 100%
- Nety Production:
- N.R.R = (i) ∑49i=15 ∑ i = 15 49 W.S.F.R x S.
- Where i – age width, S-Survival Rates.
- W.S.F.R = Female birthsFemale population Female births Female population x 1000.
- W.S.F.R X S(15 – 19) = 25 x 0.96 = 24.
- Similarly calculate for other age groups.
- Σ W.S.F.R x S = 596.62.
- ∴ M.R.R = 5 x 596.62.
NRR is always lower than GRR, because it takes into account the fact that some women will die before entering and completing their child-bearing years. Correspondingly NRR will be less than half the magnitude of the TFR.
But on the other hand, GRR has an advantage over NRR in the fact it actually measures the long-term health of the business because ultimately churn would erode expansion and upsell opportunities over time.
Median GRR is approximately 90% across all Software as a Service (SaaS) companies. For those selling into small and medium businesses, a good GRR is 80%. For Enterprise Saas, 90% is a good GRR. For very high Annual Contract Value (ACV) products, you should benchmark your GRR up to 95%.
What is the highest NRR rating?
NRR is a common method for expressing values of noise reduction or attenuation provided by different types of hearing protectors; values range from 0 to approximately 30, with higher values indicating greater amounts of noise reduction.
Noise Reduction Rating (NRR) is a measure of the effectiveness of a hearing protection device to reduce noise levels. Higher values indicate greater noise reduction. NRR values range up to approximately 30 dB. To the right is an example of the EPA label for a headset with an NRR of 33 dB.
In any tournament, a team's net run rate (say A) is calculated by deducting the average runs scored per over by the team (A) in the competition to the average runs scored against the same team (A) in the event. Now for example, on Wednesday's IPL match Sunrisers Hyderabad scored 141 runs in their allotted 20 overs.
Vital statistics include: Numbers and rates of births. Key characteristics of births, such as births by sex, location and maternal age. Numbers and rates of deaths.
Vital statistics are compilations of data on marriage, divorce, birth, and death. Births and deaths directly determine changes in the size of a population; marriages and divorces create and dissolve, respectively, the conditions under which most births occur.
The crude death rate is calculated as the number of deaths in a given period divided by the population exposed to risk of death in that period. For human populations the period is usually one year and, if the population changes in size over the year, the divisor is taken as the population at the mid-year.
John Graunt F.R.S. (1620-74): The founding father of human demography, epidemiology and vital statistics.
