Quick calculation shows you have a 4% permaban rate. The sample I took (in both december and january) showed a 2.6% permaban rate.
So, you have a higher than normal permaban rate! Though, I don't know if its statistically significant due to small sample size.
Also, the higher permaban rate may actually point toward the off said "Riot would be harsher" statement. But its such a small sample size, I wouldn't feel comfortable saying anything either way in relation to your permaban rate.