Year Data set n Expected mean visits se Observed mean visits se Results from t-tests
1 all data 181 4.64 0.12 1.86 0.1 t(360) = 18, p < .001***
1 > 1 sightings 74 4.62 0.19 3.09 0.17 t(146) = 6.1, p < .001***
2 all data 144 5.67 0.14 2.3 0.18 t(286) = 14.9, p < .001***
2 > 1 sightings 60 7.3 0.27 4.12 0.29 t(118) = 8.1, p < .001***
3 all data 40 10.8 0.39 4.62 0.61 t(78) = 8.6, p < .001***
3 > 1 sightings 31 10.8 0.46 5.68 0.68 t(60) = 6.3, p < .001***